Add 2/5 and 12/21
2/5 + 12/21 is 34/35.
Steps for adding fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 5 and 21 is 105
Next, find the equivalent fraction of both fractional numbers with denominator 105 - For the 1st fraction, since 5 × 21 = 105,
2/5 = 2 × 21/5 × 21 = 42/105 - Likewise, for the 2nd fraction, since 21 × 5 = 105,
12/21 = 12 × 5/21 × 5 = 60/105 - Add the two like fractions:
42/105 + 60/105 = 42 + 60/105 = 102/105 - 102/105 simplified gives 34/35
- So, 2/5 + 12/21 = 34/35
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 4/5+12/21 2/5+24/21 2/10+12/21 2/5+12/42 6/5+12/21 2/5+36/21 2/15+12/21 2/5+12/63 10/5+12/21 2/5+60/21 2/25+12/21 14/5+12/21 2/5+84/21 2/35+12/21