Lesson 11 Different Ways to Subtract

- Let’s subtract fractions and mixed numbers.

Warm-up Number Talk: Mixed Number Addition and Subtraction

Find the value of each expression mentally.

$3 + \frac{7}{8}$
$3 - \frac{7}{8}$
$1 \frac{5}{8} + \frac{6}{8}$
$1 \frac{5}{8} - \frac{6}{8}$

Activity 1 Challenging Differences

Problem 1

Circle all of the expressions that are equivalent to $3 \frac{5}{8}$ . Explain or show your reasoning.

$\frac{20}{8}$
$2 \frac{13}{8}$
$3 \frac{10}{16}$

Problem 2

Find the value of each expression. Explain or show your reasoning.

$3 \frac{5}{8} - \frac{3}{16}$
$3 \frac{5}{8} - 1 \frac{15}{16}$
$3 \frac{5}{8} - 1 \frac{12}{16}$

Activity 2 Find the Difference

Find the value of each difference. Explain or show your reasoning.

$9 \frac{1}{8} - 8 \frac{8}{9}$
$3 \frac{1}{2} - \frac{10}{4}$
$4 \frac{3}{5} - 1 \frac{2}{3}$

Practice Problem

Problem 1

Find the value of $2 \frac{3}{4} - \frac{1}{3}$ . Explain or show your reasoning.
Find the value of $3 \frac{2}{7} - \frac{4}{5}$ . Explain or show your reasoning.