lesson

Updated 1 month ago Β· 4 views
Imagine you need to buy 6 tickets to a theme park, and each ticket costs 24.Youdonotneedpaperoracalculatortomultiply6 \times 24$ if you know how to break numbers apart.
The Area Model and Splitting Numbers
Over 2,300 years ago, Greek mathematicians like Euclid showed that multiplying two numbers is the same as finding the area of a rectangle. When a rectangle is wide, you can split it into smaller pieces and add their areas together.
This rule is the distributive property, which states that multiplying a factor by a sum gives the same result as multiplying that factor by each addend separately: aΓ(b+c)=(aΓb)+(aΓc).
πInteractive diagram
To decompose a number means to break it down into friendlier parts, such as tens and ones.
When we rewrite 6Γ24 as (6Γ20)+(6Γ4), we are expanding the product.
Decomposing Over Addition
Let's look at another calculation: 7Γ53. Decompose 53 into tens and ones as (50+3).
7Γ53=7Γ(50+3)=(7Γ50)+(7Γ3)
Since 7Γ50=350 and 7Γ3=21, we add the two partial products: 350+21=371.
What if a factor is extremely close to an easy benchmark number like 50 or 100, but just a little below it?