MATH 8 SECTION 1.3BMULTIPLYING INTEGERS WITHPRIME COMPOSITION
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REVIEW: PRODUCTS
In how many ways can the following numbers bewritten as a product of different integers?
Note: The order of the which the integers aremultiplied does not matter because the product will beequal
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MULTIPLICATION STRATEGIES:
When multiplying two or more numbers together,sometimes it is easier to break them up and then putthem back together
One strategy that we can use is to multiply 5 by 2 tomake 10
When multiplying any number by 10, we just add azero at the end of the number
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STRATEGIES:
Split each number down to a product of as many integersas possible
When you multiply a group of integers, the order does notmatter, so you can move them around
Multiplying each 5 and 2 makes 10 (easy to multiply)
Leave the “2’s” to the end because it’s easy to double anumber
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MULTIPLYING BY 9999999’S…
When multiplying by 9, 99, 999, or 9999’s, convert thenumber to ten, hundred, or thousand and then subtractone
This is because multiplying by 1, 10, 100 and 1000 arefairly easy. The only challenge is subtracting theproduct afterwards
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SPEED MULTIPLYING :
Here’s a strategy for multiplying that is used in someAsian countries
Strategy is similar to the traditional method of but isslightly different. All carrying is done at the end
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Now we add vertically
The units digit staysand the tens digitis carried forward
PRACTICE:
