Dividing Decimals

Show your work for each problem.

1.
What is $6.4 \div 2$ ?
1. a)3.4
2. b)0.32
3. c)32
4. d)3.2
Answer: 3.2
$6.4 \div 2 = 3.2$ . The decimal point stays in the same relative position: $64 \div 2 = 32$ , so $6.4 \div 2 = 3.2$ .
2.
Calculate $9.6 \div 4$
Answer: 2.4
$9.6 \div 4 = 2.4$ . Since $96 \div 4 = 24$ , and there's one decimal place in 9.6, the answer is 2.4.
3.
Calculate $15.6 \div 3$ step by step.
Answer: 5.2
1. What is $15 \div 3$ ? 5
2. What is $6 \div 3$ (the tenths)? 2
3. Combine: What is the final answer? 5.2
4.
What is $7 \div 2$ ?
1. a)3.2
2. b)3.5
3. c)3
4. d)35
Answer: 3.5
$7 \div 2 = 3.5$ . We can write $7 = 7.0$ and divide: $7.0 \div 2 = 3.5$ .
5.
Calculate $4.8 \div 0.4$
Answer: 12
$4.8 \div 0.4 = 48 \div 4 = 12$ . Multiply both by 10 to eliminate the decimal in the divisor.
6.
Calculate $7.2 \div 0.6$ using the method of making the divisor whole.
Answer: 12
1. Multiply $7.2$ by 10: 72
2. Multiply $0.6$ by 10: 6
3. Now divide $72 \div 6$ : 12
7.
What is $6 \div 0.5$ ?
1. a)12
2. b)0.12
3. c)6.5
4. d)3
Answer: 12
$6 \div 0.5 = 12$ . Dividing by 0.5 is the same as multiplying by 2. There are 12 halves in 6.
8.
Calculate $18.9 \div 0.3$
Answer: 63
$18.9 \div 0.3 = 189 \div 3 = 63$ . We multiply both by 10 to make the divisor whole.
9.
A 4.5 kg bag of rice costs 6.75 dollars. What is the price per kilogram?
Answer: 1.5
1. What operation do we need? (divide or multiply) divide
2. Multiply the price and the weight by 10 so the divisor is a whole number. What does the weight $4.5$ become? 45
3. Now calculate $67.5 \div 45$ : 1.5
10.
What is $12.5 \div 0.25$ ?
1. a)50
2. b)500
3. c)5
4. d)0.5
Answer: 50
$12.5 \div 0.25 = 1250 \div 25 = 50$ . We multiply both by 100 to eliminate decimals.
11.
Calculate $3.42 \div 0.6$
Answer: 5.7
$3.42 \div 0.6 = 34.2 \div 6 = 5.7$ . Divide $34.2$ by $6$ : $34 \div 6 = 5$ R $4$ , then $42 \div 6 = 7$ .
12.
Calculate $8.75 \div 0.25$ step by step.
Answer: 35
1. How many decimal places does the divisor $0.25$ have? 2
2. What power of 10 should we multiply by? 100
3. What is $8.75 \times 100$ ? 875
4. What is $0.25 \times 100$ ? 25
5. Calculate $875 \div 25$ : 35
13.
Five friends share a restaurant bill of 78.50 dollars equally. How much does each person pay?
1. a)14.70 dollars
2. b)15.70 dollars
3. c)1.57 dollars
4. d)157.00 dollars
Answer: 15.70 dollars
$78.50 \div 5 = 15.70$ , so each person pays 15.70 dollars.
14.
Calculate $14.4 \div 0.12$
Answer: 120
$14.4 \div 0.12 = 1440 \div 12 = 120$ . Multiply both by 100 to make the divisor whole.
15.
A car travels 156.8 km on 8.4 liters of fuel. How many kilometers does it travel per liter? Round to 2 decimal places.
Answer: 18.67
1. We divide distance by fuel: $156.8 \div 8.4$ . Multiply the divisor $8.4$ by 10. What do you get? 84
2. Multiply the dividend $156.8$ by 10 too. What do you get? 1568
3. Calculate $1568 \div 84$ and round to 2 decimal places: 18.67