math
posted by danny on .
use mental math and the distributive property to simplify 25(99)and 19x21

Round the numbers so that they are easy to do you your head.

exsample for danny 25(99) what is the answer thanks

What she is trying to say it, change the numbers into easier number that you can multipy in your head.
Change 99 to 100
Then the question would be 25(100)
which is equal to 2500
but you added on a 25
so now you you have to add on a positive 25;
2500+25=2475
That should be the right answer.
Try doing the other one on your own.