5. Fractions

Lesson

If we can add and subtract fractions , that will help us in this lesson. Let's try a review problem now.

Find the value of \,\dfrac{3}{5}+\dfrac{3}{4}.

Worked Solution

Idea summary

Before we add or subtract fractions, we must first make sure that the fractions have the **same denominator**.

How to compare the size of statements that involve fractions.

We want to compare \dfrac{8}{12} to \dfrac{1}{12}+\dfrac{2}{4}.

a

Convert \dfrac{2}{4} into twelfths.

Worked Solution

b

Write the symbol, <, > or =, that makes the statement true:\dfrac{8}{12} ⬚ \dfrac{1}{12}+\dfrac{2}{4}

Worked Solution

Idea summary

We can use area models to compare the size of statements that involve fractions.

This video looks at comparing statements that involve mixed numbers

We want to compare 8\dfrac{9}{10}-2\dfrac{1}{5} to 6\dfrac{3}{5}.

a

Convert 2\dfrac{1}{5} and 6\dfrac{3}{5} into tenths.

Worked Solution

b

Write the symbol, <, > or =, that makes the statement true.8\dfrac{9}{10}-2\dfrac{1}{5} \,⬚ \, 6\dfrac{3}{5}

Worked Solution

Idea summary

We can use area models to compare the fraction parts of mixed number statements.

This video will show us how to write and use number sentences with fractions.

Hannah had climbed one seventh of the ladder to the roof when she realised she'd forgotten her phone, so went back down to get it.

Complete the number sentence that describes how far in total Hannah has climbed once she has returned to the bottom of the ladder.

Hannah has climbed ⬚ seventh plus ⬚ seventh of the length of the ladder.

Worked Solution

Idea summary

Evaluate the statement and then compare the values.

To help solve the statement, draw a representation (a number line or rectangle).

Solve problems involving addition and subtraction of fractions with the same or related denominators