Where does the decimals used?

Answer 1

What do you mean if you mean in multiplication after multiplying move the decimal to the left for how many numbers there were after the decimal point. if you mean in addition or subtraction the you line up the numbers and then the point stays where it was

Ex. 2.13

+31.4

---------

43.53

If you mean in division then the easiest way is to move the decimal point to the right of the divisor however many times you wish and you have to do the same with the dividend and after dividing that you have to replace however many times you move the decimal point