Add 7/21 and 12/40
7/21 + 12/40 is 19/30.
Steps for adding fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 21 and 40 is 840
Next, find the equivalent fraction of both fractional numbers with denominator 840 - For the 1st fraction, since 21 × 40 = 840,
7/21 = 7 × 40/21 × 40 = 280/840 - Likewise, for the 2nd fraction, since 40 × 21 = 840,
12/40 = 12 × 21/40 × 21 = 252/840 - Add the two like fractions:
280/840 + 252/840 = 280 + 252/840 = 532/840 - 532/840 simplified gives 19/30
- So, 7/21 + 12/40 = 19/30
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 14/21+12/40 7/21+24/40 7/42+12/40 7/21+12/80 7/21+36/40 7/63+12/40 35/21+12/40 7/21+60/40 49/21+12/40 7/21+84/40