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Unit 4 Multiplication of Whole Numbers
Copyright by The Goodheart-Willcox Co., Inc.
The upper number in a multiplication equation is the multiplicand. This is the number that is
being added repeatedly. The number below the multiplicand is the multiplier. This number
represents how many times the multiplicand will be repeatedly added. The result of a
multiplication equation is the product. Refer to the multiplication tables if you need to refresh
your skills as you study the following examples.
Always line up the figures on the right side in the units column. Multiply every digit in
the multiplicand by the number in the units column of the multiplier. Start multiplying the
multiplicand at the units column. In this example, it starts with the 3 in the multiplier’s units
column and the 2 in the multiplicand’s units column.
132
× 23
396
Next, multiply every digit in the multiplicand by the 2 in the multiplier’s tens column. Place the
results of this multiplication below the first results. However, these second results should be fi
indented so it lines up directly under the 2 in the multiplier. Then, add the results of the two
multiplication operations.
132
× 23
396
264
3,036
In multiplication problems, you often have to carry numbers. This was also done in addition
equations when the sum of a single column was 10 or higher. Since only one digit can occupy a
column, a number was carried to the next column. See the example below.
298
× 27
In the first operation, 7 fi × 8 = 56. Place the 6 in the answer and write a little 5 directly above the 9.
5
298
× 27
6
Now, multiply 7 × 9 to get 63 and add the carried 5 to it, arriving at 68. Place 8 in the answer
and a little 6 above the 2.
6 5
298
× 27
86
Multiply 7 × 2 to get 14. Add the carried 6 to the 14 to get 20. Write 20 in the answer. Always
check your accuracy.
6 5
298
× 27
2086