Lesson 3: Practice Problems

Problem 1

Here is a base-ten diagram that represents 1.13. Use the diagram to find .

Explain or show your reasoning.

A base-ten diagram that represents 1.13

Problem 2

Compute the following sums. If you get stuck, consider drawing base-ten diagrams.

Problem 3

A student said we cannot subtract 1.97 from 20 because 1.97 has two decimal digits and 20 has none. Do you agree with his statement? Explain or show your reasoning.

Problem 4

Decide which calculation shows the correct way to find and explain your reasoning.

  1. subtraction algorithm 3 tenths - 6 thousandths = 306 thousandths.
  2. subtraction algorithm, 3 tenths - 6 thousandths = 97 thousandths.
  3. subtraction algorithm, 3 tenths - 6 thousandths = 24 thousandths.
  4. subtraction algorithm, 3 tenths - 6 thousandths = 294 thousandths.

Problem 5

Complete the calculations so that each shows the correct difference.

  1. subtraction problem with blanks, 142.6 minus 1.4 equals blank blank blank .2
  2. subtraction problem with blanks, 38.60 minus 6.75 equals blank blank decimal blank 5
  3. subtraction problem with blanks, 241.76 minus 2.18 equals blank blank blank decimal blank 8

Problem 6 From Unit 5 Lesson 1

The school store sells pencils for $0.30 each, hats for $14.50 each, and binders for $3.20 each. Elena would like to buy 3 pencils, a hat, and 2 binders. She estimated that the cost will be less than $20.

  1. Do you agree with her estimate? Explain your reasoning.

  2. Estimate the number of pencils could she buy with $5. Explain or show your reasoning.

Problem 7 From Unit 4 Lesson 15

A rectangular prism measures cm by 12 cm by cm.

  1. Calculate the number of cubes with edge length cm that fit in this prism.

  2. What is the volume of the prism in ? Show your reasoning. If you are stuck, think about how many cubes with -cm edge lengths fit into .

Problem 8 From Unit 2 Lesson 12

At a constant speed, a car travels 75 miles in 60 minutes. How far does the car travel in 18 minutes? If you get stuck, consider using the table.

minutes

distance in miles