Grade 4 · Unit 2: Fractions and decimals

Percentages and ratio

Out of 100, and comparing amounts.

Percent all around

“50% off!” “90% marks!” “Battery 25%.” Percent means out of 100. 50% means 50 out of 100 – half.

Percent of a shape

25 out of 100 squares: 25%. As a fraction: 25/100 = ¼. Know these: 50% = ½, 25% = ¼, 10% = 1/10, 75% = ¾.

Percentages of amounts

50% of ৳600 = half = ৳300. 10% = divide by 10 = ৳60. 20% = 2 × 10% = ৳120.

Ratio

A ratio compares two amounts: 3 mangoes for every 2 bananas, 3 : 2. If we double the mangoes to 6, we double the bananas to 4. A proportion compares a part with the whole: 3 out of 5 fruits are mangoes.

What I learnt

• I understand percent as out of 100.
• I can find simple percentages of amounts.
• I can use ratio to compare quantities.