How do you teach multiplication by 100?
- When you multiply by 1 the answer stays the same. 21 × 1 = 21.
- When you multiply by 10, move all the digits one place to the left, putting a zero in the empty space. 21 × 10 = 210.
- When you multiply by 100, move all the digits two places to the left, putting a zero in the empty spaces. 21 × 100 = 2100.
Regarding this, what is the rule for multiplying by 100?
To multiply any number by 100, just tag TWO zeros on the end. To multiply any number by 1,000, just tag THREE zeros on the end. Note especially what happens when the number you multiply already ends in a zero or zeros. The rule works the same; you still have to tag the zero or zeros.
Keeping this in consideration, what are the multiplication strategies?
To multiply any number by 8, double the number. Then double the product and finally, double that product. To multiply any number by 9, multiply it by 10 and then subtract one set of that number. To multiply any number by 10, think of the number that is equal to that many tens.
A googol is a 1 with a hundred zeroes behind it. We can write a googol using exponents by saying a googol is 10^100. The biggest named number that we know is googolplex, ten to the googol power, or (10)^(10^100). That's written as a one followed by googol zeroes.