This lesson covers what the distributive property is and how to use it to help solve multiplication problems in your head. (Mental Math)
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The Distributive Property say that
| multiplying a number by a group of numbers added together | $5 * (7 + 4)$ |
| is the same as doing each multiplication separately | $(5 * 7) + (5 * 4) $ |
| $5 * (7 + 4)$ | $=$ | $(5 * 7) + (5 * 4)$ |
| $5 * (11)$ | $=$ | $(35) + (20)$ |
| $55$ | $=$ | $55$ |
 |
$=$ |  |
The Distributive Property can be expressed as:
a $*$ (b + c) = a $*$ b + b $*$ c
Ok, so how does this help me?
Lets say you need to by 20 baseball hats for your school team. Each hat costs \$4.97 (including tax) at DiscountMugs.
So you could multiply $20 * 4.97$
or you use the distributive property.
| $20 * (5.00$ – $0.03)$ |
| $(20 * 5.00)$ – $(20 * 0.03)$ |
| $100.00$ – $0.60$ |
| $99.40$ |
