Question

draw an area model to make like units. then add or subtract.

1. $\frac{2}{3}+\frac{6}{9}=$__ + = __
2. $\frac{1}{4}-\frac{1}{12}=$__ - = __

Explanation:

Step1: Find a common denominator for $\frac{2}{3}+\frac{6}{9}$

The common - denominator of 3 and 9 is 9. Rewrite $\frac{2}{3}$ with a denominator of 9. $\frac{2}{3}=\frac{2\times3}{3\times3}=\frac{6}{9}$.
So $\frac{2}{3}+\frac{6}{9}=\frac{6}{9}+\frac{6}{9}$

Step2: Add the fractions

$\frac{6}{9}+\frac{6}{9}=\frac{6 + 6}{9}=\frac{12}{9}=\frac{4}{3}$

Step3: Find a common denominator for $\frac{1}{4}-\frac{1}{12}$

The common - denominator of 4 and 12 is 12. Rewrite $\frac{1}{4}$ with a denominator of 12. $\frac{1}{4}=\frac{1\times3}{4\times3}=\frac{3}{12}$.
So $\frac{1}{4}-\frac{1}{12}=\frac{3}{12}-\frac{1}{12}$

Step4: Subtract the fractions

$\frac{3}{12}-\frac{1}{12}=\frac{3 - 1}{12}=\frac{2}{12}=\frac{1}{6}$

Answer:

1. $\frac{6}{9}+\frac{6}{9}=\frac{4}{3}$
2. $\frac{3}{12}-\frac{1}{12}=\frac{1}{6}$