Basic Mathematics for College Students

To multiply larger whole numbers, we can use vertical form by stacking them with
their corresponding place values lined up. Then we make repeated use of basic
multiplication facts.

1.4 Multiplying Whole Numbers 41

Self Check 1

Multiply:

Now TryProblem 19

6  54

Your solution should

look like this:

4

5

7

 8

376

Multiply whole numbers that end with zeros.

An interesting pattern develops when a whole number is multiplied by 10, 100, 1,000
and so on. Consider the following multiplications involving 8:

There is one zero in 10. The product is 8 with

one 0 attached.

There are two zeros in 100. The product is 8 with

two 0’s attached.

There are three zeros in 1,000. The product is 8 with

three 0’s attached.

There are four zeros in 10,000. The product is 8 with

four 0’s attached.

These examples illustrate the following rule.

8  1 0 , 0 0 0  8 0 , 0 0 0

8  1 , 0 0 0  8 , 0 0 0

8  1 0 0  8 0 0

8  1 0  8 0

2

Multiplying by 10, 100, 1,000, and So On

To find the product of a whole number and and so on, attach

the number of zeros in that number to the right of the whole number.

1 0 , 1 0 0 , 1 , 0 0 0 ,

EXAMPLE (^1) Multiply:
Strategy We will write the multiplication in vertical form. Then, working right to
left, we will multiply each digit of 47 by 8 and carry, if necessary.
WHY This process is simpler than treating the problem as repeated addition and
adding eight 47’s.
Solution
To help you understand the process, each step of this multiplication is explained
separately. Your solution need only look like the laststep.
Vertical form
We begin by multiplying 7 by 8.
The product is 376.
Multiply 4 by 8. The product is 32.
To the 32, add the carried 5 to get 37.
Write 7 in the tens column and the
3 in the hundreds column of the answer.

4

5

7

 8

3 7 6

Multiply 7 by 8. The product is 56.

Write 6 in the ones column of the answer,

and carry 5 to the tens column.

4

5

7

 8

6

4 7

 8

Tens column

Ones column



8  47