add: $ \ 3 \ \frac{1}{2} \ + \ 2 \ \frac{1}{4} \ + \ 4 \ \frac{1}{6}$
Use the LCD which is 12. Add the fractional part. And then add the whole numbers.
Thus, $3 \ \frac{1}{2} \ + \ 2 \ \frac{1}{4} \ + \ 4 \ \frac{1}{6} \ = \ 9 \ \frac{11}{12}$.
subtract: $12 \ \frac{5}{6} \ - \ 7 \ \frac{3}{4}$
Study other examples below which shows how to simplify answers:
Example 1: $ \ 1 \ \frac{2}{5} \ + \ 9 \ \frac{7}{10}$
Write equivalent fractions using the LCD.
Simplify: $ \ 10 \ + \ \frac{11}{10} \ = \ 10 \ + \ 1 \ \frac{1}{10} \ = \ 11 \ \frac{1}{10}$
Example 2: $ \ 3 \ \frac{2}{10} \ + \ 1 \ \frac{3}{4}$
What happened? We re-write fraction $3\frac{8}{40}$ so that its numerator is greater, such that 48 > 30 before subtracting.
Let's check our answer:
$1 \ \frac{18}{40} \ + \ 1 \ \frac{3}{4} \ = \ 1 \ \frac{18}{40} \ + \ 1 \ \frac{30}{40}$
$= \ 2 \ \frac{48}{40}$ or $3\frac{2}{10}$
