Introduction to Distributive Property with Whole Numbers

This lesson covers what the distributive property is and how to use it to help solve multiplication problems. Also covered is how to use it to do mental math.

 
 
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) $

 

$5 * (7 + 4)$ $=$ $(5 * 7) + (5 * 4)$
$5 * (11)$ $=$ $(35) + (20)$
$55$ $=$ $55$
distributive property $=$ 5754

 
The Distributive Property can be expressed as:
               a $*$ (b + c) = a $*$ b + b $*$ c
 
Ok, so how does this help me?distributive law

 
Lets say you need to by 15 baseball hats for your school team. Each hat costs \$5 at DiscountMugs.
 
So you could multiply $5 * 15$
or you use the distributive property.

$5 * (10 + 5)$
$(5 * 10) + (5 * 5)$
$50 + 25$
$75$