What is the reduced form of 84 over 198?

Answer 1

84 / 198 = ???

They are both even, so divide the numerator and denominator by 2:

84 / 198 = 42 / 99

This time they are both divisible by 3 (see tip below on how I knew this):

42 / 99 = 14/33

14/33 is the reduced form, it cannot be further simplified.

Extra Tip:

To see if a number is divisible by 3, sum up the digits and keep doing it until you have a single digit:

E.g., In 42, 4+2=6

In 99, 9+9=18; 1+8=9

If the result (called a digital root) is equal to 3, 6, or 9 than the number is divisible by 3.

If the digital root is equal to 3, 6, or 9 and it is even than the number is also divisible by 6.

If the digital root is equal to 9, than the number is also divisible by 9.

This tip helps with doing a number of a problems in your head.