Add 42/70 and 1/21
42/70 + 1/21 is 68/105.
Steps for adding fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 70 and 21 is 210
Next, find the equivalent fraction of both fractional numbers with denominator 210 - For the 1st fraction, since 70 × 3 = 210,
42/70 = 42 × 3/70 × 3 = 126/210 - Likewise, for the 2nd fraction, since 21 × 10 = 210,
1/21 = 1 × 10/21 × 10 = 10/210 - Add the two like fractions:
126/210 + 10/210 = 126 + 10/210 = 136/210 - 136/210 simplified gives 68/105
- So, 42/70 + 1/21 = 68/105
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 84/70+1/21 42/70+2/21 42/70+1/42 42/70+3/21 42/70+1/63 42/70+5/21 42/70+7/21