METHOD 1 – Prime Factoring
Reduce 36/60 to lowest terms .
• Factor the numerator and denominator into prime factors.
• Cancel common factors in numerator and denominator, and
multiply the remaining factors.
METHOD 2 – Divisibility
Reduce 36/60 to lowest terms.
• Using the divisibility hints on sheet 2, check for the
even divisibility of prime numbers into both
the numerator and denominator. Since 2 divides into both 36 & 60 evenly:
• Continue using the divisibility rules . Since 2 divides
into both 18 & 30 evenly:
• Finally, since 3 divides into both 9 & 15 evenly:
There are no remaining common prime factors, so the final
answer is 
.
HINTS FOR DIVISIBILITY OF SOME COMMON PRIME FACTORS
| |
|
Example |
| Check the last digit |
If even (0,2,4,6,8) Then number is
divisible by 2 |
76 |
6 is even |
 |
| Add all digits |
If the sum is divisible by 3 The
number is
divisible by 3 |
123 |
1+2+3=6
6 is divisible by 3 |
 |
| Is the last digit 0 or 5? |
The number is divisible by 5 |
415 |
Last digit is 5 |
 |
Are all of the digits the
same? |
If there is an even number of digits,
the
number is divisible by 11. |
66 |
All digits are the
same, and there
are an even
number of digits. |
 |
| Add up every other digit. |
If the sums are the same, the number
is
divisible by 11. |
253 |
2+3=5
5=5 |
 |
Now, try the practice problems below.
PRACTICE PROBLEMS: Reduce the following fractions
to lowest terms.
Answers
