Multiplying and dividing pronumerals Write the numbers together and then the pronumerals together,...

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Multiplying and dividing pronumerals Write the numbers together and then the pronumerals together, then simplify

Transcript of Multiplying and dividing pronumerals Write the numbers together and then the pronumerals together,...

Page 1: Multiplying and dividing pronumerals Write the numbers together and then the pronumerals together, then simplify.

Multiplying and dividing pronumerals

Write the numbers together and then the pronumerals

together, then simplify

Page 2: Multiplying and dividing pronumerals Write the numbers together and then the pronumerals together, then simplify.

What we know already about multiplicationIs 3x4 = 4x3 ?Is 2x3x2 = 2x2x3 ? (we can change the order when we

multiply)

If it doesn’t matter which order we multiply, we can move numbers and letters around without changing the answer.

YES!

YES!

Page 3: Multiplying and dividing pronumerals Write the numbers together and then the pronumerals together, then simplify.

We have a shorthand for writing numbers and letters when they are multiplied together.

6 x c = 6c 6 x c = c x 6 = c6(but mathematicians almost never

write the letter first)

Page 4: Multiplying and dividing pronumerals Write the numbers together and then the pronumerals together, then simplify.

Is 2xa = ax2 = 2a ?

If a = 4, is 2 x 4 = 4 x 2?

YES!

Page 5: Multiplying and dividing pronumerals Write the numbers together and then the pronumerals together, then simplify.

Example

6 x 3c= 6 x 3 x c= 18 x c= 18c

Page 6: Multiplying and dividing pronumerals Write the numbers together and then the pronumerals together, then simplify.

Example 2

• 11e x 6f• = 11 x 6 x e x f• = 66 x e x f • = 66ef

Page 7: Multiplying and dividing pronumerals Write the numbers together and then the pronumerals together, then simplify.

Example 3

5d x -2c x e x 4=5 x d x -2 x c x e x 4=5 x -2 x 4 x d x c x e= -10 x 4 x d x c x e= -40 x d x c x e=-40dce

Page 8: Multiplying and dividing pronumerals Write the numbers together and then the pronumerals together, then simplify.

Division• remember divide is the opposite to multiply

eg. 10 ÷ 5 = 2 And 2 x 5 = 10

• 10a ÷ 5a• = 10 x a 5 x a• = 10 x a (cancel out)

5 x a• = 2

1 = 2