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Unit 4 Multiplication of Whole Numbers
Copyright by The Goodheart-Willcox Co., Inc.
Smaller Multiplier
It does not matter which of the two numbers is positioned as the multiplier or multiplicand.
Both will provide the same results. However, it may be easier to place the smaller number as
the multiplier. This will result in having fewer rows of numbers to add.
1286 27
× 27 × 1286
9002 162
25720 2160
34,722 5400
Same
27000
34,722
Denominate Numbers
How denominate numbers work in an equation is based on the operation of an equation.
For instance, we already know that denominate numbers must have the same units to be added
or subtracted. However, in multiplication and division equations, denominate numbers do
not need to have the same units. In a multiplication equation, the units of measurements are
combined.
When denominate numbers with different units of measurement are multiplied together,
they form a new unit of measurement. See the example below.
12 lb × 7′ = 84 ft-lb
While the numbers are multiplied, the pound and foot units are combined to form foot-
pounds (ft-lb). These compound units can be formed by multiplication and undone by division.
When denominate numbers sharing the same unit of measurement are multiplied together,
they form a squared unit. See the example below.
7″ × 8″ = 56 in2 ″
Multiplying two inch measurements together forms a product measured in inches squared
(in2). More information on denominate numbers in multiplication equations will be covered in
later units on measurement.