Conversion a mixed number 2 1/
4
to a improper fraction: 2 1/4 = 2 1/
4
= 2 · 4 + 1/
4
= 8 + 1/
4
= 9/
4
To find a new numerator:
a) Multiply the whole number 2 by the denominator 4. Whole number 2 equally 2 * 4/
4
= 8/
4
b) Add the answer from previous step 8 to the numerator 1. New numerator is 8 + 1 = 9
c) Write a previous answer (new numerator 9) over the denominator 4.
Two and one quarter is nine quarters
Conversion a mixed number 1 3/
8
to a improper fraction: 1 3/8 = 1 3/
8
= 1 · 8 + 3/
8
= 8 + 3/
8
= 11/
8
To find a new numerator:
a) Multiply the whole number 1 by the denominator 8. Whole number 1 equally 1 * 8/
8
= 8/
8
b) Add the answer from previous step 8 to the numerator 3. New numerator is 8 + 3 = 11
c) Write a previous answer (new numerator 11) over the denominator 8.
One and three eighths is eleven eighths
Subtract: 9/
4
- 11/
8
= 9 · 2/
4 · 2
- 11/
8
= 18/
8
- 11/
8
= 18 - 11/
8
= 7/
8
For adding, subtracting, and comparing fractions, it is suitable to adjust both fractions to a common (equal, identical) denominator. The common denominator you can calculate as the least common multiple of both denominators - LCM(4, 8) = 8. In practice, it is enough to find the common denominator (not necessarily the lowest) by multiplying the denominators: 4 × 8 = 32. In the following intermediate step, it cannot further simplify the fraction result by canceling.
In other words - nine quarters minus eleven eighths is seven eighths.