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Multiplication Madness...

 

We need to know a different ways to multiply...you might be asked to use a specific method to get your answer in a test like the PARCC. They are all related and all contain partial products.

 

 

 

The Expanded Algorithm 1

 

https://www.youtube.com/watch?v=4yP1PPLZt0Q

 

https://www.youtube.com/watch?v=kMiIeyTMrck

 

 

 

The Area Model

 

https://learnzillion.com/lessons/23-solve-1-by-1-digit-multiplication-problems-using-area-model

 

https://learnzillion.com/lessons/24-solve-2-by-2-digit-multiplication-problems-using-area-model

 

https://www.youtube.com/watch?v=5QZnVBlMhNs

 

https://www.youtube.com/watch?v=3EIBMzDdCd0

 

 

 

The Partial Product Method 

 

https://learnzillion.com/lessons/21-solve-1-by-2-digit-multiplication-problems-using-partial-products

 

https://learnzillion.com/lessons/22-solve-2-by-2-digit-multiplication-problems-using-partial-products

 

https://www.youtube.com/watch?v=htN1CDwo-VY

 

https://www.youtube.com/watch?v=q-6Owg7joIQ

 

 

 

 

Using the Distributive Property

 

 

https://www.khanacademy.org/math/cc-fourth-grade-math/cc-4th-mult-div-topic/cc-4th-area-models/v/2-digit-multiplication-with-grid

 

 

 

Remember the Properties of Multiplication (you NEED to know these)

 

Commutative Property: 

When two numbers are multiplied together, the product is the same regardless of the order of the multiplicands. 

For example 4 x 2 = 2 x 4

 

Associative Property: 

When three or more numbers are multiplied, the product is the same regardless of the grouping of the factors. 

For example (2 x 3) x 4 = 2 x (3 x4)

 

Multiplicative Identity Property: 

The product of any number and one is that number.

For example 5 x 1 = 5.

 

Distributive Property: 

The sum of two numbers times a third number is equal to the sum of each addend times the third number. 

For example 4 x (6 + 3) = 4 x 6 + 4 x 3

 

 

 

 

 

Below are some fast multiplication tricks you can use in mental math...you might use these in a contest link the Math Olympiad.

 

 

 

Multiplication Tricks (you do NOT need to know this)

 

 

https://www.youtube.com/watch?v=PYrgjMubh-c

 

 

 

https://www.youtube.com/watch?v=SV1dC1KAl_U

 

 

 

https://www.youtube.com/watch?v=Rgw9Ik5ZGaY