NZ Level 3
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Addition and Subtraction using models
Lesson

You may have learned how to add or subtract fractions using a number line. Now let's look at how we can use area models to help us add and subtract fractions.

 

Adding fractions with area models

Watch this video to learn about adding fractions using area models.

 

Subtracting fractions with area models

Now watch this video to learn about subtracting fractions with area models.

Remember!

Look carefully at area models to see different fractions.

We can use area models to change fractions to their equivalent fraction so the denominators are the same and then solve.

 

Examples

Question 1

In the image below, $\frac{1}{2}$12 has been shaded red and $\frac{1}{4}$14 has been shaded blue.

  1. Write the addition that describes the image.

  2. What is the total shaded?

QUESTION 2

The image below shows $\frac{1}{3}$13 of the rectangle shaded.

  1. What is the equivalent fraction in fifteenths? $\frac{1}{3}=\frac{\editable{}}{15}$13=15

  2. We now want to take away $\frac{4}{15}$415.

    What is the answer to $\frac{1}{3}-\frac{4}{15}$13415?

QUESTION 3

In the image below, $\frac{2}{5}$25 has been shaded red and $\frac{1}{10}$110 has been shaded blue.

  1. Write the addition that describes the image.

  2. What is the total shaded?

Outcomes

NA3-1

Use a range of additive and simple multiplicative strategies with whole numbers, fractions, decimals, and percentages.

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