Add 21/70 and 3/80
21/70 + 3/80 is 27/80.
Steps for adding fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 70 and 80 is 560
Next, find the equivalent fraction of both fractional numbers with denominator 560 - For the 1st fraction, since 70 × 8 = 560,
21/70 = 21 × 8/70 × 8 = 168/560 - Likewise, for the 2nd fraction, since 80 × 7 = 560,
3/80 = 3 × 7/80 × 7 = 21/560 - Add the two like fractions:
168/560 + 21/560 = 168 + 21/560 = 189/560 - 189/560 simplified gives 27/80
- So, 21/70 + 3/80 = 27/80
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 42/70+3/80 21/70+6/80 63/70+3/80 21/70+9/80 21/70+15/80 21/70+21/80