Fraction to Decimal:
You take the numerator and denominator and divide them both together in order to get your decimal.
ex: 2 divided by 4 = 0.5
Decimal to Percent:
Take your decimal and times it by 100. In order to do it without calculator, you move the decimal point to your right of how much 0's you have.
ex: 0.5 x 100 = 40%
Percent to Decimal:
Its just like converting decimal to percent but divide it by 100. When doing it without calculator, you put a decimal point on the last number (on the right) and move it to your left of how much 0's the number your dividing with.
ex: 40 divided by 100= 0.40
Decimal to fraction:
Say it. If your decimal number is in the tenths, your denominator would be 10, if its hundredths, your denominator would be 1000, if its thousandths,your denominator would be 1000.
ex: 0.5= 5/10, 0.55= 55/100, 0.557= 557/1000
Percent to fraction:
Take your percent and make it your numerator, your denominator would always be 100.
ex: 55%= 55/100