Comparing Fraction

 Comparing Fraction 

The vertically and crosswise method can be adapted very easily to compare two fraction 

Example - which is larger 

7            4

-    or     -

9            5

1. multiply crosswise from top left to bottom right  7 × 5 = 35

2. Multiply crosswise the other way, top right to bottom left 4 × 9 = 36. 

3. If the first number is bigger than the first fraction is the larger, and vice versa

 7         4

 -    <    - 

9          5

Ordering fraction by Elimination and Retention

this method uses products of one numerator with the remaining denominators .

Example : place order of size  3

3        5     2

-        -      -

4       8      3

1. eliminate the first denominator and multiply 3×8×3=72 (3/4)

2. eliminate the second denominator  5×4×3=60 (5/8)

3. eliminate the third denominator 2×4×8=64  (2/3)

4. the size of the product gives the relative size of the fraction 60,64,72.

indicate the order is 

 5     2    3

 -     -     -

8     3    4

which fraction is closer to 1 or any other number

example :  Which fraction is closer to 1  5/7 or 7/5 ??

The distance between 1 and 5/7 is 2/7 (1- 5/7 =2/7)

The distance between 1 and 7/5 is 2/5  (1 - 7/5 = 2/5)

7 > 5 ⟹$⟹$ 1/7 < 1/5 ⟹$⟹$ 2/7 < 2/5

Therefore, 5/7 is closer to 1