Add 21/56 and 5/90
21/56 + 5/90 is 31/72.
Steps for adding fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 56 and 90 is 2520
Next, find the equivalent fraction of both fractional numbers with denominator 2520 - For the 1st fraction, since 56 × 45 = 2520,
21/56 = 21 × 45/56 × 45 = 945/2520 - Likewise, for the 2nd fraction, since 90 × 28 = 2520,
5/90 = 5 × 28/90 × 28 = 140/2520 - Add the two like fractions:
945/2520 + 140/2520 = 945 + 140/2520 = 1085/2520 - 1085/2520 simplified gives 31/72
- So, 21/56 + 5/90 = 31/72
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 42/56+5/90 21/56+10/90 63/56+5/90 21/56+15/90 21/56+25/90 21/56+35/90