We are learning to find percentages of 3 digit numbers.

We are learning to find percentages of 3 digit numbers.

What does % mean?

per

for every

cent

100

To find 1% of a number ÷ by 100 Find 1% of 225

225 ÷ 100 (move all digits 2 places to the right)

225. 2 .25

1% of 225 =

To find 10% of a number ÷ by 10 Find 10% of 376

376 ÷ 10 (move all digits 1 place to the right)

376. 37.6

10% of 376 =

Can we use this information To find 11% of a number?

10% + 1% = 11%

Find 11% of 352 352 ÷ 100 = 3.52

352. 3.52

352 ÷ 10 = 35.2

352. 3 5.2 3.52 + 35.2 38 .72

Find 2% of 453 1% of 453

1% x 2 = 2%

453 ÷ 100 =4.53 The decimal point goes between the 9 and the 0. There are 2 digits after the decimal point in the sum so we need 2 digits after the decimal point in the answer

4.53 x 2 1

9.0 6

2% of 453 =

2x3=6 2 x 5 = 10 (carry the 1) 2x4=8+1=9

Use these methods to find

12% of 563

Hint: add together 10%, 1% and 1%

56.3 + 5.63 + 5.63 =

16% of 285

Hint: add together 10%, 6 x 1%

28.5 + (6 x 2.85) =

Can you find 20% of 621?

Hint: 20% = 10% + 10% or 10% x 2

621 ÷ 10 = 62.1 62.1 + 62.1 124.2

62.1 x 2 124.2

20% of 621 = 124.2