FractionConcepts1: Lesson: Shaded and unshaded parts: Shaded and unshaded parts of an area model or number line

Shaded and unshaded parts of an area model or number line

In this lesson students will use number bonds to decompose one whole into two or more fractions.

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Problem 1: Draw the fraction using the area model and number line. Then use a number bond to represent what is emphasized and what is not emphasized.

Fraction

Area

Number line

Number bond

$\frac{3}{5}$

$\frac{3}{5}$ of the rectangle is shaded. $\frac{2}{5}$ is unshaded.

We hopped $\frac{3}{5}$ of the way to 1. We have $\frac{2}{5}$ of the way until we reach 1.

The number bond allows students to numerically decompose the one whole thing into a sum of smaller fractions. In this case $\frac{3}{5}+\frac{2}{5} = 1$ . (Officially adding fractions is not a Grade 3 standard. It appears in Grade 4.)

Problem 2: Draw the fraction using the area model and number line. Then use a number bond to represent what is emphasized and what is not emphasized.

Fraction

Area

Number line

Number bond

$\frac{6}{8}$

$\frac{6}{8}$ of the rectangle is shaded. $\frac{2}{8}$ is unshaded.

We hopped $\frac{6}{8}$ of the way to 1. We have $\frac{2}{8}$ of the way until we reach 1.

Problem 3: Complete the number bond. Draw a shape that has shaded and unshaded parts that match the completed number bond.

If students cannot identify the missing fraction mentally, then they are encouraged to draw a model to help them find the missing fraction.

Sometimes we want to take a number bond and then decompose it further into its unit fractions. For students, this helps them remember that $\frac{3}{5}$ is really $\frac{1}{5}+\frac{1}{5}+\frac{1}{5}$ .

Problem 4: Write a two-part number bond for this figure. Then decompose the number bond into unit fractions.

Press [Next] to begin the 5 practice problems.