Add 20/8 and 25/21
1st number: 2 4/8, 2nd number: 1 4/21
20/8 + 25/21 is 155/42.
Steps for adding fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 8 and 21 is 168
Next, find the equivalent fraction of both fractional numbers with denominator 168 - For the 1st fraction, since 8 × 21 = 168,
20/8 = 20 × 21/8 × 21 = 420/168 - Likewise, for the 2nd fraction, since 21 × 8 = 168,
25/21 = 25 × 8/21 × 8 = 200/168 - Add the two like fractions:
420/168 + 200/168 = 420 + 200/168 = 620/168 - 620/168 simplified gives 155/42
- So, 20/8 + 25/21 = 155/42
In mixed form: 329/42
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 40/8+25/21 20/8+50/21 20/16+25/21 20/8+25/42 60/8+25/21 20/8+75/21 20/24+25/21 20/8+25/63 20/40+25/21 20/56+25/21