Add 21/7 and 20/40
1st number: 3 0/7, 2nd number: 20/40
21/7 + 20/40 is 7/2.
Steps for adding fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 7 and 40 is 280
Next, find the equivalent fraction of both fractional numbers with denominator 280 - For the 1st fraction, since 7 × 40 = 280,
21/7 = 21 × 40/7 × 40 = 840/280 - Likewise, for the 2nd fraction, since 40 × 7 = 280,
20/40 = 20 × 7/40 × 7 = 140/280 - Add the two like fractions:
840/280 + 140/280 = 840 + 140/280 = 980/280 - 980/280 simplified gives 7/2
- So, 21/7 + 20/40 = 7/2
In mixed form: 31/2
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 42/7+20/40 21/14+20/40 21/7+20/80 63/7+20/40 21/7+60/40 21/35+20/40 21/49+20/40