Section D: Practice Problems Divide Decimals

Section Summary

Details

In this section we learned to divide with decimals. We studied different ways to find a quotient like $3 \div 0.1$ . We can draw a diagram which shows that there are 10 groups of 0.1 in each whole so there are $3 \times 10$ or 30 groups of 0.1 in 3 wholes: $3 \div 0.1 = 30$ .

Three diagrams. Each squares. Each partitioned into 10 rows of 10 of the same size squares.

We can also think about place value. We know 3 is 30 tenths and 0.1 is 1 tenth, so $3 \div 0.1$ is equivalent to $30 \div 1$ which has the value 30. We also can use multiplication to find the value of $3 \div 0.1$ . We know that $10 \times 0.1 = 1$ and $30 \times 0.1 = 3$ so this also shows that $3 \div 0.1 = 30$ .

Problem 1 (Lesson 22)

Find the value of $1 \div 0.01$ . Use the diagram if it is helpful.
Jada says that there are 100 hundredths in 1 so $1 \div 0.01$ is 100. Do you agree with Jada? Show or explain your reasoning.

Problem 2 (Lesson 23)

Find the value of $2 \div 0.2$ . Use the diagram if it is helpful.
Find the value of $21 \div 0.2$ .

Problem 3 (Lesson 23)

Here is a diagram.

Explain or show how the diagram shows $200 \div 25$ . What is the value of the expression?
Explain or show how the diagram shows $2 \div 0.25$ . What is the value of the expression?

Problem 4 (Lesson 24)

Find the value of each expression. Explain or show your reasoning.

$0.2 \div 5$ . Use the diagram if it is helpful.
$6 \div 3$
$6 \div 0.3$

Problem 5 (Exploration)

Noah has a scale that weighs to the nearest ounce. The table shows the weights of different numbers of paper clips in ounces.

paper clips	weight
$1$	$0$
$10$	$0$
$20$	$1$
$25$	$1$
$50$	$2$
$100$	$3$

How many ounces do you think each paper clip weighs? Explain or show your reasoning.

Problem 6 (Exploration)

The daily recommended allowance of vitamin C for a 5th grader is 0.05 grams.

A vitamin C tablet has 1 gram of vitamin C. How many times the daily recommended allowance of vitamin C is one vitamin C tablet? Use the diagram if it is helpful.
A large orange has 0.18 grams of vitamin C. How many times the daily recommended allowance of vitamin C is in a large orange? Use the diagram if it is helpful.