Lesson 1

Mystery Bags

Let's make predictions based on what we know.

Problem 1

Lin is interested in how many of her classmates watch her favorite TV show, so she starts asking around at lunch. She gets the following responses:

  • yes
  • yes
  • yes
  • no
  • no
  • no
  • no
  • no
  • no
  • no
  • yes
  • no
  • no
  • no

If she asks one more person randomly in the cafeteria, do you think they will say “yes” or “no”? Explain your reasoning.

Problem 2

An engineer tests the strength of a new material by seeing how much weight it can hold before breaking. Previous tests have held these weights in pounds:

  • 1,200
  • 1,400
  • 1,300
  • 1,500
  • 950
  • 1,600
  • 1,100

Do you think that this material will be able to hold more than 1,000 pounds in the next test? Explain your reasoning.

Problem 3

A company tests two new products to make sure they last for more than a year.

  • Product 1 had 950 out of 1,000 test items last for more than a year.
  • Product 2 had 150 out of 200 last for more than a year.

If you had to choose one of these two products to use for more than a year, which one is more likely to last? Explain your reasoning.

Problem 4

Put these numbers in order from least to greatest.

  • \(\frac{1}{2}\)
  • \(\frac{1}{3}\)
  • \(\frac{2}{5}\)
  • 0.6
  • 0.3

 

Problem 5

A small staircase is made so that the horizontal piece of each step is 10 inches long and 25 inches wide. Each step is 5 inches above the previous one. What is the surface area of this staircase?

A small staircase consisting of 3 steps is indicated.
(From Unit 7, Lesson 15.)