To identify basic multiplication facts and properties

MENTAL MATH Find each sum:

1.2 + 2 + 2 + 2 2.5 + 5 + 5 3.8 + 8 + 8 +8 4.9 + 9 + 95.4 + 4 + 4 + 4 + 46.7 + 7 + 7 + 7 + 77.1 + 1 + 1 + 1 + 1 + 1 + 1

Multiplication Properties

Commutative PropertyAssociative PropertyIdentity PropertyZero PropertyDistributive Property

Why Should you Learn about the Properties of Multiplication?

It helps you solve problems without working

them out.It helps with mental math.It makes understanding math easier.

Commutative PropertyThe order of the numbers doesn’t change the result (answer to the problem)

6 x 4 = 4 x 6

Commutative Property

9 X 3 = 3 X w56 X p = 11 X 56q X 8 = 8 X 45 X 9 = r X 5

Commutative Property 9 X 3 = 3 X 956 X 11 = 11 X 564 X 8 = 8 X 45 X 9 = 9 X 5

Associative PropertyThe grouping of the factors doesn’t change the answer.

(4 x 2) x 3 = 24 4 x (2 x 3) = 24

(5 x 1) x 6 = 30 5 x (1 x 6) = 30

Associative Property3 x (4 x 2) = (n x 4) x 24 x (p x 7) = (4 x 1) x 75 x (7 x 2) = (5 x 7) x n(2 x z) x 5 = 2 x (8 x 5)

Is this Associative?5 X (n X 2) = (2 X 5) X 5 Watch out!

Associative Property3 X (4 X 2) = (3 X 4) X 24 X (1 X 7) = (4 X 1) X 75 X (7 X 2) = (5 X 7) X 2(2 X 8) X 5 = 2 X (8 X 5)

Is this Associative? No, it’s commutative.5 X (5 X 2) = (2 X 5) X 5

Identity PropertyAny number multiplied by 1 will give you the original number.

23,487 X 1 = 23,487

Identity Property234 X 1 = zq X 2,567 = 2,56798,765 X d = 98,765

Answers are on the next slide.

Identity Property

234 X 1 = 2341 X 2,567 = 2,56798,765 X 1 = 98,765

Zero PropertyWhen any number is multiplied with zero, the answer is zero.

If one factor is O, the product is O.

Example: 98,756,432 X 0 = 0

Zero Property

7,547,598,375 X o = 0758,375,937 X 0 = 00 X 75,879,705 = 0

Distributive PropertyMultiplying the sum (or difference) by a number is the same as multiplying each number in the sum (or difference) by the number and adding (or subtracting) the product.

9 X (20 - 3) = (9 X 20) – (9 X 3)8 X (40 + 5) = (8 X 40) + (8 X 5)8 X 45 = (8 X 40) + (8 X 5)

Distributive Property4 X 509 = (4 X 500) + (4 X m)6 X 310 = (6 X n) + (6 X 10)s X 205 = (5 X 200) + (5 X 5)195 X 5 = (200 X 5) – (5 X t)

Test Yourself

1. 9 X 3 = 3 X w2. 3 X (4 X 2 ) = (n X 4) X 23. 234 X 1 = z4. 56 X p = 11 X 565. 7,547,598,375 X c = 06. q X 8 = 8 X 47. 5 X (7 X 2) = (5 X 7) X n8. 4 X 509 = (4 X 500) + (4 X

m)9. 6 X 310 = (6 X n) + (6 X

10)

10. (2 X z) X 5 = 2 X (8 X 5)11. q X 2,567 = 2,56712. 12. 195 X 5 = (200 X 5) – (5

X t)13. z X 75,879,705 = 014. 98,765 X d = 98,76515. 5 X 9 = r X 516. s X 205 = (5 X 200) + (5 X 5)17. 4 X (p X 7) = (4 X 1) X 718. 758,375,937 X 0 = b

Rewrite each equation with the correct answer, and write the name of the property.

Test Yourself Answers1. 9 X 3 = 3 X 9 Commutative2. 3 X (4 X 2) = (3 X 4) X 2

Associative3. 234 X 1 = 234 Identity4. 56 X 11 = 11 X 56

Commutative5. 7,547,598,375 X 0 = 0 Zero6. 4 X 8 = 8 X 4 Commutative7. 5 X (7 X 2) = (5 X 7) X 2

Associative8. 4 X 509 = (4 X 500) + (4 X

9) Distributive9. 6 X 310 = (6 X 300) + (6 X

10) Distributive

10. (2 X 8) X 5 = 2 X (8 X 5) Associative

11. 1 X 2,567 = 2,567 Identity12. 195 X 5 = (200 X 5) – (5 X

5) Distributive13. 0 X 75,879,705 = 0 Zero14. 98,765 X 1 = 98,765

Identity15. 5 X 9 = 9 X 5 Commutative16. 5 X 205 = (5 X 200) + (5 X

5) Distributive17. 4 X (1 X 7) = (4 X 1) X 7

Associative18. 758,375,937 X 0 = 0 Zero

How did you do?18 correct Excellent17 correct Very Good16 - 15 correct Good14 - 13 correct Passing12 – 0 correct You need more

practice.