Unit fractions and fractions on a number line (grade 3) · lesson

Parts of a whole

💡 The bottom number tells how many equal parts make the whole, and the top number tells how many parts you have.

Cut a whole into equal parts. Count all the parts. That number goes on the bottom.

Count the parts you have, eat, or shade. That number goes on the top.

🧠 Let's work it out

Look at the picture. It has 6 equal parts. 3 are shaded. What fraction is shaded?

What do you think comes next?

💡 1 over a number is one equal part, and a fraction with the same top and bottom is one whole.

1/5 means 1 of 5 equal parts. A fraction with 1 on top is called a unit fraction.

The more parts you cut, the smaller each part is. So 1/9 is closer to 0 than 1/2.

When you have all the parts, you have the whole. 3 thirds make 1 whole, so 3/3 = 1.

🧠 Let's work it out

How many thirds make 1 whole?

What do you think comes next?

💡 On a number line, each equal jump from 0 to 1 is one part, so count the jumps to name the spot.

Split the space from 0 to 1 into equal parts. If there are 8 parts, each jump is 1/8.

Start at 0. Count the jumps. 5 jumps of 1/8 lands on 5/8.

Fractions near 0 are small amounts. Fractions near 1 are almost a whole.

🧠 Let's work it out

A line from 0 to 1 has 8 equal parts. Where is the 5th mark?

What do you think comes next?

💡 A number line can keep going past 1, and you keep counting the same size jumps.

A number line can go from 0 to 2. Each whole is cut into the same number of parts.

Keep counting jumps past 1. If each jump is 1/3, then 4 jumps is 4/3. That is 1 whole and 1/3 more.

🧠 Let's work it out

A line goes from 0 to 2. Each whole has 3 parts. Where is the 4th mark?

What do you think comes next?