Page 73 - Basic College Mathematics with Early Integers

50 C HAPTE R 1 I THE WHOLE NUMBERS

This is how we multiply whole numbers. When multiplying whole numbers, we will
use the following notation.
First: Next:
5 5
4 8 4 8
* 7 * 7
Write 6 in the
3 3 6 7 8=56 ones place and 3 3 6 7 4+5=28+5=33
#
#
carry 5 to the tens
place.
The product of 48 and 7 is 336.

PRACTICE 3 Example 3 Multiply:
Multiply.
a. 36 b. 132 a. 25 b. 246
* 4 * 9 * 8 * 5
Solution:
4 b. 2 3
a. 25 246
* 8 * 5
200 1230
Work Practice 3

To multiply larger whole numbers, use the following similar notation. Multiply
89 * 52.
Step 1 Step 2 Step 3
1 4
89 89 89
* 52 * 52 * 52

178 ; Multiply 89 * 2. 178 178
4450 ; Multiply 89 * 50. 4450
4628 Add.
The numbers 178 and 4450 are called partial products. The sum of the partial prod-
ucts, 4628, is the product of 89 and 52.

PRACTICE 4 Example 4 Multiply: 236 * 86
Multiply.
Solution: 236
a. 594 b. 306
* 86
* 72 * 81
1 416 ; 6(236)
18 880 ; 80(236)
20,296 Add.
Work Practice 4

Example 5 Multiply: 631 * 125
PRACTICE 5
Multiply. Solution: 631

a. 726 b. 288 * 125
* 142 * 4 3 155 ; 5(631)

12 620 ; 20(631) Copyright 2012 Pearson Education, Inc.
Answers 63 100 ; 100(631)
3. a. 144 b. 1188
78,875 Add.
4. a. 42,768 b. 24,786
5. a. 103,092 b. 1152 Work Practice 5