Lesson 18: Practice Problems

Problem 1

Andre and Jada both found  using the partial quotients method, but they did the calculations differently, as shown here.

Andre's and Jada's division solution for 657 divided by 3 using partial quotients.

  1. How is Jada’s work the same as Andre’s work? How is it different?

  2. Explain why they have the same answer.

Problem 2

Here is a long-division calculation of .

A long division solution 917 divided by 7

  1. There is a 7 under the 9 of 917. What does this 7 represent?

  2. What does the subtraction of 7 from 9 mean?

  3. Why is a 1 written next to the 2 from ?

Problem 3

Han’s calculation of is shown here.

A long division solution for 972 divided by 9

  1. Find .

  2. Use your calculation of to explain how you know Han has made a mistake.

  3. Identify and correct Han’s mistake.

Problem 4

Find each quotient.

  1. long division problem, 465 divided by 5.
  2. long division problem, 924 divided by 12.
  3. long division problem, 1107 divided by 3.

Problem 5

The mass of one coin is 16.718 grams. The mass of a second coin is 27.22 grams. How much greater is the mass of the second coin than the first? Show your reasoning.

Problem 6

One micrometer is a millionth of a meter. A certain spider web is 4 micrometers thick. A fiber in a shirt is 1 hundred-thousandth of a meter thick.

  1. Which is wider, the spider web or the fiber? Explain your reasoning.

  2. How many meters wider?