MS Scientific Reasoning — every video script, narration first

1. A student drops the same toy with a small, a medium, and a large parachute and times each fall. What does she change on purpose?

1. the parachute's size ✓
2. the time each fall takes

1. A student wants to find out whether a wet towel dries faster in the sun. She hangs one towel in the sun and one in the shade and times how long each takes to dry. Which thing does she change on purpose?

1. how long each towel takes to dry
2. where each towel hangs ✓
3. the size of the towels

2. Tobias adds one, two, then three spoonfuls of baking soda to the same amount of vinegar and measures how high the foam rises each time. Is the height of the foam the thing he changes on purpose?

1. yes
2. no ✓

3. A student drops the same ball from 50 cm, 100 cm, and 150 cm and measures how high it bounces. Is the drop height the thing she changes on purpose?

1. yes ✓
2. no

4. A student tests whether a paper airplane flies farther with a paper clip on its nose. He throws the same plane from the same spot, first without the clip and then with it. Which thing does he change on purpose?

1. the spot he throws from
2. whether the plane has a paper clip ✓
3. how far the plane flies

1. A student adds one, two, then three drops of dish soap to bowls of water and counts the bubbles. Which is the independent variable?

1. the number of bubbles
2. the number of drops of dish soap ✓

1. A student wants to find out whether a longer string makes a pendulum swing more slowly. She hangs the same metal nut from strings of three lengths and counts the swings in one minute. Which is the independent variable?

1. the number of swings in one minute
2. the metal nut on the string
3. the length of the string ✓

2. A student tests whether a toy car rolls farthest on tile, on carpet, or on wood. He gives the same car the same push each time and measures how far it rolls. Which is the independent variable?

1. the surface the car rolls on ✓
2. how far the car rolls
3. the push he gives the car

3. Tobias times how long an ice cube takes to melt in a cold room, a warm room, and a hot room. He says the independent variable is the melting time, because that is the number that comes out different each time. Is Tobias correct?

1. yes
2. no ✓

4. In a test, the one thing you change on purpose has a scientific name. What is it called? Type the two words. (typed)

Accepted: independent variable · an independent variable · the independent variable

1. A student counts a cricket's chirps per minute in a cool and a warm room. What does he measure to see what the change did?

1. the number of chirps ✓
2. how warm the room is

1. A student wants to find out whether a heavier backpack makes a walk slower. He walks the same path with three backpacks of different masses and times each walk. Which thing does he measure to see what the change did?

1. the time each walk takes ✓
2. the mass of the backpack
3. the length of the path

2. A student counts the paper clips a magnet lifts through one sheet of paper and through three sheets. Is the number of paper clips lifted the thing she measures to see what the change did?

1. yes ✓
2. no

3. A student puts one slice of bread in the refrigerator, one on the counter, and one in a warm cupboard and counts the days until mold appears on each. Is the place each slice sits the thing she measures to see what the change did?

1. yes
2. no ✓

1. A student counts the seeds that sprout in cold soil and in warm soil, to see what the warmth did. Which is the dependent variable?

1. how warm the soil is
2. the number of seeds that sprout ✓

1. A student wants to find out whether plant food gives a tomato plant more tomatoes. She gives three plants 0, 5, and 10 drops of plant food a week and counts the tomatoes on each plant. Which is the dependent variable?

1. the number of drops of plant food
2. the number of tomatoes on each plant ✓
3. the kind of plant

2. Tobias tests whether a thicker candle burns for longer. He says the dependent variable is the candle's thickness, because he decides it. Is Tobias correct?

1. yes
2. no ✓

3. A student measures how far a toy truck rolls with small wheels and with big wheels, to see what the wheel size did. What is the distance the truck rolls called?

1. the dependent variable ✓
2. the independent variable

4. In a test, the thing you measure to see what the change did has a scientific name. What is it called? Type the two words. (typed)

Accepted: dependent variable · a dependent variable · the dependent variable

1. A student tests whether a fizzy drink goes flat faster in a wide glass or a tall glass. What must she keep the same?

1. the amount of drink in each glass ✓
2. the shape of each glass

1. A student pulls a toy catapult's arm back a short way, a medium way, and a long way to fling a cotton ball, and measures how far the ball flies. Which thing must she keep the same?

1. the cotton ball she flings ✓
2. how far she pulls the arm back
3. how far the ball flies

2. A student wants to know whether more coats of paint take longer to dry. She paints one, two, or three coats on same-size boards and times the drying. Must she keep the number of coats the same?

1. yes
2. no ✓

3. A student tests whether a bigger sail makes a toy boat cross a paddling pool faster. She uses the same boat and the same fan with sails of three sizes. Must she keep the fan's setting the same?

1. yes ✓
2. no

4. A student tests whether a steel marble or a glass marble knocks a wooden block farther. He rolls each marble down one track from a mark 30 cm up the slope and measures how far the block slides. Which thing must he keep the same?

1. which marble he rolls
2. how far the block slides
3. the height each marble starts from ✓

1. A student tests whether a wooden or a metal spoon warms up faster in one mug of hot cocoa. Which is a control variable?

1. the kind of spoon
2. the cocoa ✓

1. A student tests whether water evaporates faster from a wide dish or a narrow dish. She pours 200 mL of water into each dish and leaves both on one kitchen shelf for a day. Which is a control variable?

1. the shape of the dish
2. the amount of water in each dish ✓
3. how much water is left after a day

2. A student tests whether a long straw or a short straw makes a louder whistle. She blows the same way each time and reads a sound meter. What is the way she blows called?

1. the independent variable
2. the dependent variable
3. a control variable ✓

3. A student tests whether more coils of wire make an electromagnet pick up more pins. She winds 10, 20, and 30 coils around the same nail and counts the pins each time. What is the number of coils called?

1. the independent variable ✓
2. the dependent variable
3. a control variable

4. In a test, the things you keep the same, so they cannot affect the result, have a scientific name. What are they called? Type the two words. (typed)

Accepted: control variable · a control variable · the control variable · control variables

1. A student tests whether a bigger wheel makes a toy windmill turn faster in front of a fan. Which thing must she keep the same?

1. the windmill's distance from the fan ✓
2. the size of the windmill's wheel
3. how fast the windmill turns

2. A student counts how many beads he can thread in one minute wearing thin gloves, thick gloves, or no gloves. What is the number of beads called?

1. the independent variable
2. the dependent variable ✓
3. a control variable

3. A student rolls a marble from three different starting heights, and the starting height is the one thing she changes on purpose. What is the starting height called in her test? Type the two words. (typed)

Accepted: independent variable · an independent variable · the independent variable

1. A toy walks farther with more turns of its key. The table shows five results. Which result does not fit the pattern of the rest?

1. the result at 3 turns
2. the result at 4 turns ✓

1. A student drops the same paper helicopter five times from the same height and times each fall. The table shows the results. Which trial's result does not fit the pattern of the rest?

1. Trial 3
2. Trial 4 ✓
3. Trial 5

2. A student reads the temperature of a cup of hot water every 5 minutes as it cools. The table shows the results. Which reading does not fit the pattern of the rest?

1. the reading at 0 minutes
2. the reading at 5 minutes
3. the reading at 10 minutes ✓

3. A student times one swing of a pendulum five times. The table shows the results, and trial 5 is the longest. Does trial 5's result fit the pattern of the rest?

1. yes ✓
2. no

4. A student measures how far a rubber band flies five times. Her fourth reading sits far from her other four readings. What should she do with the fourth reading?

1. keep it and check that trial ✓
2. cross it out and move on
3. change it to match the others

1. A thermometer by a pond has read about 15 degrees Celsius at noon every day this week. Which sentence is right about tomorrow's noon reading?

1. It is likely to be about 15 degrees Celsius. ✓
2. It is certain to be about 15 degrees Celsius.

1. A school bus has arrived at a stop at about 8:05 on every school day for a month. What does the pattern tell about tomorrow's bus?

1. It is certain to arrive at about 8:05.
2. It is likely to arrive at about 8:05. ✓
3. The pattern tells nothing about tomorrow.

2. A student weighs her dog on the first day of each month, and for twelve months the reading has been about 20 kilograms. Why does the pattern make next month's reading likely, not certain?

1. Twelve readings are too few to show a pattern.
2. A dog's weight never follows a pattern.
3. Next month can be different from the months before. ✓

3. A student has tested a glue stick ten times, and the glue held every time. He says the glue will certainly hold next time. Is he right?

1. yes
2. no ✓

4. A kitten has gained about 100 grams each week for six weeks. Which sentence is right about next week?

1. The kitten is likely to gain about 100 grams. ✓
2. The kitten is certain to gain about 100 grams.
3. The kitten will gain much less than 100 grams.

1. A student spins a top once and it spins for 25 seconds. Which of these could have been different on that one spin?

1. a bump from her elbow on the table ✓
2. the weight of the top she spins

1. A student drops a paper cup once from a shelf and times its fall at 2.8 seconds. Which of these could have been different on that one drop?

1. the cup's size
2. the floor it landed on
3. a gust of air from an open window ✓

2. A student rolls a marble once down a groove and measures how far it goes. Could a wobble of his hand as he let go have been different on that one roll?

1. yes ✓
2. no

3. A student rolls a marble once down a groove and measures how far it goes. Could the marble's mass have been different on that one roll?

1. yes
2. no ✓

4. A student stretches a rubber band once and lets it fly 3 meters. Why is this one result weak evidence on its own?

1. Something unusual about that one try could have made it a fluke. ✓
2. A distance of 3 meters is too short a flight to count.
3. A tape measure cannot measure a flight of 3 meters.

1. A student wants a trustworthy result for how far a beanbag slides when she pushes it across the floor. Which makes her result more trustworthy?

1. measuring one slide very carefully
2. repeating the push and getting close distances ✓

1. A student soaks up water with the same sponge three times and weighs the water each time. The table shows the results. What do the three different numbers show?

1. Careful repeats give numbers that are close, not the same. ✓
2. One of the three trials was a mistake made by the student.
3. The scale is broken and needs to be replaced.

2. A student times how long a spinning top keeps spinning, five times, and all five times sit close together. Why is her result more trustworthy than a single timing would be?

1. If one timing had been a fluke, the other four would have shown it. ✓
2. Five timings take much more time to do than one timing does.
3. Five timings give exactly the same number every single time.

3. A student measures how far a toy car rolls, three times, and the three distances are close but not the same. She says the different numbers mean she made a mistake. Is she right?

1. yes
2. no ✓

4. A student wants to know how fast he catches a dropped ruler. Which gives the more trustworthy result?

1. five catches with close results ✓
2. one careful catch, measured precisely

1. A student counts the drops a dropper gives for one squeeze, five times. Four counts sit close together and one sits far from all of them. What should he do with the count that sits far from the others?

1. cross it out
2. keep it and check that squeeze ✓
3. change it to match the other four

2. A streetlight outside a student's window has come on at about 7 o'clock every evening for a month. Which sentence is right about this evening?

1. It is likely to come on at about 7 o'clock. ✓
2. It is certain to come on at about 7 o'clock.
3. The pattern tells nothing about this evening.

3. A student measures how high a popcorn kernel jumps when it pops, three times, and the three heights are close but not the same. What do the three different heights show?

1. One of the three measurements must have been a mistake.
2. Careful repeats give numbers that are close, not the same. ✓
3. The kernel jumps a little higher every single time.

1. A student measures the trunk width of four trees of different ages. The table shows the readings. Do these two change together?

1. yes ✓
2. no

1. A student keeps a fish tank under a lamp. For four days she notes how long the lamp was on and the water's temperature at bedtime. Do these two change together?

1. yes ✓
2. no

2. A teacher lists four students' shoe sizes beside their spelling scores. Do these two change together?

1. yes
2. no ✓

3. A student turns a speaker's volume setting up step by step and weighs the speaker on a balance each time. Do these two change together?

1. yes
2. no ✓

4. A student reads the air temperature at four distances from a heater. Do these two change together?

1. yes ✓
2. no

5. A student notes how many minutes she practiced free throws each afternoon and how many of 10 she scored that evening. Do these two change together?

1. yes ✓
2. no

1. A student changes only a ramp's height, and the same ball rolls farther. Do the results support that the higher ramp made it roll farther?

1. yes ✓
2. no

1. A survey of thirty families finds that the families with more houseplants had fewer colds last winter. Do these results support that the plants stopped the colds?

1. yes
2. no ✓

2. A student warms four jars of the same honey to 20, 30, 40 and 50 °C and drops the same marble into each. The warmer the honey, the faster the marble sinks. Do these results support that warmer honey let the marble sink faster?

1. yes ✓
2. no

3. A survey of three hundred gardens finds that the gardens with more earthworms grow bigger carrots. Do these results show only that the two change together?

1. yes ✓
2. no

4. A student bakes one tray of cookies with extra butter in a hotter oven and one tray with less butter in a cooler oven. The first tray comes out browner. Do these results support that the extra butter made the cookies browner?

1. yes
2. no ✓

5. A classmate reads that towns with more libraries have fewer burglaries, and says the libraries must be stopping burglaries. Is the classmate correct?

1. yes
2. no ✓

1. In a town, the months with more sunglasses sold are the months with more sunburns. Which is the better explanation?

1. Sunny weather is behind both. ✓
2. Sunglasses cause sunburn.

1. In a town, the days with more umbrellas carried are the days with more car accidents. Which third thing could be behind both?

1. the umbrellas
2. the car accidents
3. rainy weather ✓

2. At a fire station, the fires that bring out more fire trucks are the fires that do more damage. Which third thing could be behind both?

1. the size of the fire ✓
2. the number of fire trucks
3. the amount of damage

3. A classmate reads that the weeks when more students wear mittens to school are the weeks with more students off sick, and says the mittens must be making students ill. Is the classmate correct?

1. yes
2. no ✓

4. In a park, the weeks with more birds singing are the weeks with more flowers out. Which sentence gives a third thing behind both?

1. Spring weather brings the birds and the flowers. ✓
2. The birds come back and their singing opens the flowers.
3. The flowers open and their scent calls the birds to sing.

1. A survey finds that children who read more have bigger vocabularies. Do the results say which way the cause runs?

1. yes
2. no ✓

1. A survey finds that students who eat more vegetables have fewer cavities. One way the cause could run is that the vegetables protect their teeth. Which sentence gives the other way?

1. Students with healthy teeth chew vegetables easily, so they eat more of them. ✓
2. Students who eat more vegetables also brush their teeth more often, so they get fewer cavities.
3. Vegetables and cavities are not linked, so the survey means nothing.

2. A survey finds that people who spend more time outdoors feel happier. Could the cause run from feeling happier to spending more time outdoors?

1. yes ✓
2. no

3. A classmate reads that students who play more video games have lower grades, and says the cause could run either way: the games could be pulling the grades down, or struggling students could be turning to games. Is the classmate correct?

1. yes ✓
2. no

4. In a town, the streets with more trees have houses that sell for more money. Which sentence gives a way the cause could run from the houses to the trees?

1. Trees make a street cooler, so its houses sell for more.
2. The streets with more trees are also closer to the park.
3. Owners of expensive houses plant and keep more trees. ✓

1. Children who eat more fish have sharper eyesight. In a fair test of whether fish is the cause, which must be kept the same?

1. how much fish each child eats
2. how much screen time each child has ✓

1. A survey finds that students who practice the piano for more hours a week have higher memory scores. A class plans a fair test of whether the practice is the cause. Which is the one thing they should change on purpose?

1. the memory score
2. the hours of piano practice ✓
3. each student's bedtime

2. In the same fair test of piano practice and memory, which must the class keep the same for both groups?

1. the memory test the students take ✓
2. the hours of piano practice
3. the students' memory scores at the end

3. In the same fair test of piano practice and memory, what does the class measure to see what the change did?

1. each student's memory score ✓
2. the hours of piano practice
3. the number of students in each group

4. A survey finds that students who use a standing desk finish homework faster. Which plan is a fair test of whether the desk is the cause?

1. Compare the students who already use standing desks with the students who sit, on the same homework.
2. Give half the class standing desks, keep the homework and the deadline the same, and time both halves. ✓
3. Ask the students who use standing desks whether the desk makes them faster, and write down the answers.

5. A survey finds that students who walk to school are fitter. A teacher compares the fitness of students who already walk with the fitness of students who already ride the bus. Is this a fair test of whether walking is the cause?

1. yes
2. no ✓

1. In one class, the pencil users scored higher on one spelling test than the pen users. Which conclusion says only what the results showed?

1. Pencils make you a better speller on every test.
2. On this test, the pencil users in this class scored higher. ✓

1. In one school this year, the students who joined the chess club raised their grades more than the other students. Conclusion: chess makes students smarter. Does this conclusion claim more than the evidence supports?

1. yes ✓
2. no

2. In one test of ten bean plants, the plants given more water grew taller. Conclusion: more water always makes plants grow taller. Does this conclusion claim more than the evidence supports?

1. yes ✓
2. no

3. A town counted bike riders on one Saturday and found more riders on the sunny side of the river. Conclusion: on that Saturday, more riders used the sunny side. Does this conclusion claim more than the evidence supports?

1. yes
2. no ✓

4. On one night, the students in a group who slept more than eight hours scored higher on a memory game the next morning. Conclusion: in this group, the longer sleepers scored higher on that morning's game. Does this conclusion claim more than the evidence supports?

1. yes
2. no ✓

5. In one class, the students who sat near the window scored higher on one reading test. Conclusion: sitting by a window improves reading. Does this conclusion claim more than the evidence supports?

1. yes ✓
2. no

1. A survey of forty gardens finds that the gardens with more bird feeders have more butterflies. Do these results support that the feeders brought the butterflies?

1. yes
2. no ✓

2. In a town, the mornings with more cars that will not start are the mornings with more frozen pipes. Which third thing could be behind both?

1. the cars that will not start
2. the frozen pipes
3. very cold weather ✓

3. In one class, the students who chewed gum scored higher on one spelling test. Conclusion: gum improves spelling. Does this conclusion claim more than the evidence supports?

1. yes ✓
2. no