Question

consider the expression. mentally estimate the sum or difference. circle to show your estimate.

1. $\frac{3}{8}+\frac{1}{4}$

less than 1 between 1 and 2 greater than 2

1. $\frac{5}{9}+\frac{2}{3}$

less than 1 between 1 and 2 greater than 2

1. $\frac{3}{4}-\frac{3}{8}$

less than 1 between 1 and 2 greater than 2

1. $\frac{15}{10}-\frac{4}{5}$

less than 1 between 1 and 2 greater than 2

Explanation:

Step1: Estimate $\frac{3}{8}+\frac{1}{4}$

$\frac{1}{4}=\frac{2}{8}$, so $\frac{3}{8}+\frac{2}{8}=\frac{5}{8}<1$.

Step2: Estimate $\frac{5}{9}+\frac{2}{3}$

$\frac{2}{3}=\frac{6}{9}$, so $\frac{5}{9}+\frac{6}{9}=\frac{11}{9}$, and $1<\frac{11}{9}<2$.

Step3: Estimate $\frac{3}{4}-\frac{3}{8}$

$\frac{3}{4}=\frac{6}{8}$, so $\frac{6}{8}-\frac{3}{8}=\frac{3}{8}<1$.

Step4: Estimate $\frac{15}{10}-\frac{4}{5}$

$\frac{4}{5}=\frac{8}{10}$, so $\frac{15}{10}-\frac{8}{10}=\frac{7}{10}<1$.

Answer:

1. less than 1
2. between 1 and 2
3. less than 1
4. less than 1