Decimal Study Guide
Addition and Subtraction
- Always line up the decimal points.
Example:
14.5+6.357
=
6.375
+14.500
* You can always add zeroes to the right of the numbers that come after a decimal point.
Make sure that you add the zeros when you are subtracting.
Multiplication
- You do not need to line up the decimal points!
- Count the decimal places in both factors and then move the decimal that number to the
left in your answer.
Example:
4.04 x .2
=
4.04
x .2
.808
*If you need to move the decimal more places than your answer has add zeroes to the left
of your answer.
Division
divisor: the number you are dividing by
dividend: the number being divided
quotient: the answer
quotient
divisor dividend
- First make your divisor a whole number by moving the decimal to the right.
- Move the decimal in the dividend the same number of places you moved it in the
divisor.
- Now, bring the decimal point up to where your quotient will be.
Example:
4.04 ÷ .2
=
.
.2 4.04
Remainders
- Add at least three zeroes do your dividend and if it still hasn’t ended, or repeated, write
the remainder as a fraction.
remainder
divisor
- Then simplify the fraction