Lesson 15: Practice Problems

Problem 1

For each subtraction problem, select the correct calculation.

    1. subtraction algorithm, 7.2 minus 3.67 equals 3.05
    2. subtraction algorithm, 0.72 minus 3.67 equals 3.05
    3. subtraction algorithm, 7.20 minus 3.67 equals 3.53

    1. subtraction algorithm, 1.6 minus 1.4 equals 0.2
    2. subtraction algorithm, 16.0 minus 1.40 equals 0.20
    3. subtraction algorithm, 16.0 minus 1.4 equals 14.6

Problem 2

Explain how you could find the difference of 1 and 0.1978.

Problem 3

A bag of chocolates is labeled to contain 0.384 pound of chocolates. The actual weight of the chocolates is 0.3798 pound.

  1. Are the chocolates heavier or lighter than the weight stated on the label? Explain how you know.

  2. How much heavier or lighter are the chocolates than stated on the label? Show your reasoning.

Problem 4

Complete the calculations so that each shows the correct sum.

  1. calculation with missing digit, 1 point 0 3 6 plus an unknown quantity with four digits is equal to 4.
  2. calculation with missing digits, 0 point 7 3 8 plus an unknown quantity with four digits is equal to 1.
  3. calculation with missing digits, 0 point 5 1 3 7 plus an unknown quantity with five digits is equal to 1.

Problem 5

A shipping company is loading cube-shaped crates into a larger cube-shaped container. The smaller cubes have side lengths of feet, and the larger shipping container has side lengths of 10 feet. How many crates will fit in the large shipping container? Explain your reasoning.

Problem 6

For every 9 customers, the chef prepares 2 loaves of bread.

  1. Here is double number line showing varying numbers of customers and the loaves prepared. Complete the missing information.

    A double number line for number of customer and loaves of bread. Customers is labeled 0, 8, blank, 27, blank. Bread is labeled 0, 2, 4, blank, blank.

  2. The same information is shown on a table. Complete the missing information.

    customers

    loaves

  3. Use either representation to answer these questions.

    • How many loaves are needed for 63 customers?

    • How many customers are there if the chef prepares 20 loaves?

    • How much of a loaf is prepared for each customer?