Fractions and decimals

Fractions and decimals: I can make equivalent fractions, add and subtract fractions, compare decimals, and match fractions, decimals and percentages.

1. This bar is cut into 5 equal parts, and 2 parts are shaded: 2/5.

   Now each part is cut into 2. There are 10 parts, and 4 are shaded: 4/10.

   The shaded amount has not changed, so 2/5 = 4/10. These are equivalent fractions.

   2 × 2 = 4 and 5 × 2 = 10. The top (numerator) and the bottom (denominator) were both multiplied by 2.

   Picture: A bar cut into 5 equal parts, with 2 parts shaded. It is labelled 2/5. Each part is then cut into 2, making 10 parts with 4 shaded: 4/10.

2. This bar has 12 equal parts, and 9 are shaded: 9/12.

   The bar below has 4 equal parts, and 3 are shaded: 3/4. Both bars have the same amount shaded.

   To simplify 9/12, divide the top and the bottom by the same number: 9 ÷ 3 = 3 and 12 ÷ 3 = 4.

   So 9/12 = 3/4. No number bigger than 1 divides both 3 and 4, so 3/4 is in its simplest form.

   Picture: A bar cut into 12 equal parts, with 9 parts shaded. It is labelled 9/12. Below it, a bar cut into 4 equal parts with 3 parts shaded, labelled 3/4.

3. Your turn: This bar has 10 equal parts, and none of them are shaded yet. Tap parts to shade them, so that the shaded amount is equal to 1/2.

   Picture: A bar cut into 10 equal parts, with 0 parts shaded.

   Set the picture to your answer.

   Answer

   The answer: 5

   Shade 5 parts. 5/10 = 1/2, because 1 × 5 = 5 and 2 × 5 = 10.

   Picture: A bar cut into 2 equal parts, with 1 part shaded. It is labelled 1/2. Each part is then cut into 5, making 10 parts with 5 shaded: 5/10.

Words to know

numerator:

The top number of a fraction. It counts the parts we have.

denominator:

The bottom number of a fraction. It says how many equal parts make the whole.

equivalent:

Worth the same amount. 1/2 and 2/4 are equivalent fractions.