Add:
`2/7 + 1/7 + 3/7`
= `(2 + 1 + 3)/7`
= `6/7`
`5 1/5+2 1/7`
`3 1/5+2 1/3`
Subtract:
`5 1/2-3 1/3`
Add the following fractions
`3/9 + 7/9`
`2/9 + 1/9`
The sum of two fractions is always a fraction.
Solve:
`3/10 + 7/15`
`4/9 + 2/7`
`5/7 + 1/3`
Complete the addition-subtraction box.