Basic Mathematics for College Students

4.4 Dividing Decimals 359

WHYTo divide a decimal by a whole number, we divide as if working with whole
numbers.

Solution
Step 1

Step 2Now divide using the four-step division process:estimate, multiply, subtract,
and bring down.

In Section 1.5, we checked whole-number division using multiplication.
Decimal division is checked in the same way:The product of the quotient and the
divisor should be the dividend.

The check confirms that 42.6 6 7.1.

7.1

(^6) 42.6
Quotient
Divisor
Dividend

7.1

 6

42.6

Ignore the decimal points and divide as if working with whole numbers.

After subtracting 42 from 42, bring down the 6 and continue to divide.

The remainder is 0.

7.1

(^6)  42.6
 42
06
 6
0

.

6  42. 6

Place a decimal point in the quotient that lines up

with the decimal point in the dividend.

EXAMPLE (^2) Divide:
StrategySince the divisor is a whole number, 28, we will write the problem in
long division form and place a decimal point directly above the decimal point in
71.68. Then we will divide as if the problem was.
WHYTo divide a decimal by a whole number, we divide as if working with whole
numbers.
Solution
We can use multiplication to check this result.
The check confirms that 71.68 28 2.56.

2.56

28 71.68

2.56

 28

2048

5120

71.68

Ignore the decimal points and divide as if working

with whole numbers.

After subtracting 56 from 71, bring down the 6

and continue to divide.

After subtracting 140 from 156, bring down the 8

and continue to divide.

The remainder is 0.

2.56

28 71.68

 56

15 6

 14 0

1 68

 1 68

0

Write the decimal point in the quotient (answer) directly

above the decimal point in the dividend.

7,168 28

71.68 28

Self Check 2

Divide:

Now TryProblem 19

101.44 32