Sunday, April 19, 2009

Multiplying decimals

When multiplying decimals:

1. Ignore the decimal point
2. Add the number of digits to the right of the point of the numbers you are multiplying
3. Starting from the right of the answer, place that number of digits before the decimal point (add zeros if you have to)

Example:

.2 * .4

1. Ignore digits so 2*4 = 8
2. Count numbers 1 and 1, so 2 total
3. Count over two from right of answer so 0.08

Now

0.03 * 0.004

1. Ignore digits: 3*4 = 12
2. Count digits: 2 and 3 so 5 total
3. Count over: 0.00012

also 1.33 * 3.44

1. Ignore digits so 133*344 = 45752
2. Count: 2 and 2 so 4
3. Count over: 4.5752

Nice!

1 comment:

April Peterson said...

This makes it so easy!!