## abz_tech 4 years ago what is a fast way to multiply decimals, eg: 25 x 0.5, 17 x 0.75. also what is a fast way to multiply 2 digit numbers eg: 90 x 91, 32 x 31. thx, and ofcourse without using calculators i mean

1. TheHero

Well, I write down 90 x91 and then multiply 1x0 then 1x9. After that I multiple 9x0 and then 9x9. Add the two answers!! :DD There you go 8190

2. abz_tech

:o!

3. abz_tech

tyvm!

4. TheHero

For the decimal one. Think your adding coins. .25.+.50! It's .75! :3

5. abz_tech

hmm ok

6. strobe

If you have simple decimals with only 2 decimal places e.g. 0.75 you can just mulitply by 75 and then divide by 100 at the end by just shifting the decimal point 2 places to the left.

7. TheHero

If it's something hard like, .0192*.473 It's pretty simple. the same as multiplying! .0192 x.274 _______ 8 36 4 0 14 63 7 0 4 18 2 0 ______ add all of that up! .0052608 how do you know where to put the decimals? add each number to right of the decimal! .0192=4 .274=3 _________ 8 numbers to the left. If you don't have eight numbers you add zeros until you right 8! :DD Yay!

8. TheHero

until you have 8**