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Try it and predict: 7th grade math

Experimental vs. theoretical (long-run relative frequency). A free 7th grade lesson plan, a question set with answers and a printable sheet with its key. Copy it and make it yours.

Lesson plan

Goal

  • Students can do this: experimental vs. theoretical (long-run relative frequency).

Teach (10 min)

  • Expected count = probability × number of tries. If it rains 3/10 of days, in 50 days expect 3/10 × 50 = 15 rainy days.
  • An experiment gives an estimate: 24 shots in out of 80 means the estimated chance is 24/80 = 3/10.
  • Work one example on the board while students say each step aloud, then do one together.

Practise (15 min)

  • Students work the printable sheet in pairs, then alone.
  • Or practise it as a game with no sign-up: https://peabody.kids/math/chance.expected?lesson=7-chance-expected-1&at=7

Exit ticket (5 min)

  • Three questions on a slip:
  • 1. The chance that a train is late is 1/5. Out of 20 trips, about how many trips will be late?
  • 2. 15 out of 20 students surveyed ride a bike to school. Estimate the probability that a student chosen at random rides a bike. (Any fraction with the right value counts, so you do not have to reduce it.)
  • 3. In 50 spins, a spinner landed on blue 39 times. Estimate the probability that it lands on blue. (Any fraction with the right value counts, so you do not have to reduce it.)

Question set

10 questions that read in words, easiest first. Questions that need a picture are on the printable sheet below.

  1. The chance that a train is late is 1/5. Out of 20 trips, about how many trips will be late?
  2. 15 out of 20 students surveyed ride a bike to school. Estimate the probability that a student chosen at random rides a bike. (Any fraction with the right value counts, so you do not have to reduce it.)
  3. In 50 spins, a spinner landed on blue 39 times. Estimate the probability that it lands on blue. (Any fraction with the right value counts, so you do not have to reduce it.)
  4. A basketball player makes 1/10 of free throws. Out of 70 free throws, about how many will the player make?
  5. A spinner lands on red 3/4 of the time. If it is spun 40 times, about how many times will it land on red?
  6. A basketball player makes 3/10 of free throws. Out of 30 free throws, about how many will the player make?
  7. A seed grows into a plant 1/4 of the time. If 32 seeds are planted, about how many will grow?
  8. A spinner lands on red 1/10 of the time. If it is spun 80 times, about how many times will it land on red?
  9. The chance that a train is late is 1/4. Out of 16 trips, about how many trips will be late?
  10. In 10 spins, a spinner landed on blue 6 times. Estimate the probability that it lands on blue. (Any fraction with the right value counts, so you do not have to reduce it.)
Answers
  1. 4 late trips
  2. 3/4
  3. 39/50
  4. 7 free throws
  5. 30 times
  6. 9 free throws
  7. 8 seeds
  8. 8 times
  9. 4 late trips
  10. 3/5

Printable sheet

Name: ____________________   Date: ____________

Try it and predict (7th grade)

  1. The chance that a train is late is 1/5. Out of 30 trips, about how many trips will be late?
  2. A spinner lands on red 3/10 of the time. If it is spun 30 times, about how many times will it land on red?
  3. The chance that a train is late is 3/4. Out of 8 trips, about how many trips will be late?
  4. A seed grows into a plant 1/10 of the time. If 60 seeds are planted, about how many will grow?
  5. In 20 spins, a spinner landed on blue 15 times. Estimate the probability that it lands on blue. (Any fraction with the right value counts, so you do not have to reduce it.)
  6. A baker checked 20 loaves and found 5 that were burnt. Estimate the probability that a loaf is burnt. (Any fraction with the right value counts, so you do not have to reduce it.)
  7. A seed grows into a plant 1/5 of the time. If 20 seeds are planted, about how many will grow?
  8. In 10 spins, a spinner landed on blue 8 times. Estimate the probability that it lands on blue. (Any fraction with the right value counts, so you do not have to reduce it.)
  9. A baker checked 80 loaves and found 73 that were burnt. Estimate the probability that a loaf is burnt. (Any fraction with the right value counts, so you do not have to reduce it.)
  10. In 100 spins, a spinner landed on blue 77 times. Estimate the probability that it lands on blue. (Any fraction with the right value counts, so you do not have to reduce it.)
  11. A seed grows into a plant 40% of the time. If 40 seeds are planted, about how many will grow?
  12. The chance of rain on any day is 0.8. In 200 days, about how many rainy days would you expect?
Key
  1. 6 late trips
  2. 9 times
  3. 6 late trips
  4. 6 seeds
  5. 3/4
  6. 1/4
  7. 4 seeds
  8. 4/5
  9. 73/80
  10. 77/100
  11. 16 seeds
  12. 160 rainy days

Written by Peabody from its own skill pages. Free, no ads, no sign-in. Children can practise this on Peabody. More from teachers: teacher-shared resources.