LI: To find a percentage of an amount S.C: . I can use ...LI: To find a percentage of an amount...
Transcript of LI: To find a percentage of an amount S.C: . I can use ...LI: To find a percentage of an amount...
LI: To find a percentage of an amount
S.C:
. I can use fractional equivalences to find a percentage of an amount.
. I can use bar models to help organise my solutions.
. I can choose a preferred method to finding a percentage of an amount.
Fractions and Percentages
Key equivalents you need to know:
50% =
25% =
75% =
10% =
1
2
1
4
3
4
1
10
Percentages of Amounts
Calculate 50% of 60
50% = 1
2
1
2of 60 = 60 ÷ 2
= 30
Find 50% of 246
Percentages of Amounts
Calculate 25% of 60
25% = 1
4
1
4of 60 = 60 ÷ 4
= 15
Find 25% of 460
Percentages of Amounts
Calculate 10% of 60
10% = 1
10
1
10of 60 = 60 ÷ 10
= 6
Find 10% of 450
Percentages of Amounts
Calculate 20% of 60
First calculate 10%
10% = 60 ÷ 10
= 6
If 10% = 6, then 20% = 6 x 2 = 18
Find 20% of 360
Percentages of Amounts
Calculate 30% of 260
First calculate 10%
10% = 260 ÷ 10
= 26
If 10% = 26, then 30% = 26 x 3 = 78
Find 30% of 620
Percentages of Amounts
Calculate 5% of 400
First calculate 10%
10% = 400 ÷ 10
= 40
5% is half of 10%
10% = 40 so 5% = 20
Find 5% of 240
Percentages of Amounts
Calculate 15% of 800
First calculate 10%
10% = 800 ÷ 10
= 80
5% = half of 10% = 40
15% = 10% + 5% = 80+40 = 120
Find 15% of 240
Percentages of Amounts
Calculate 15% of 60
First calculate 10%
10% = 60 ÷ 10 = 6
5% = 3
15% = 9
Can you calculate:
15% of 4800
Now find 35% of 1200
Now find 35% of 2460
Finding 75% of amounts
Finding 75% of amounts:
To find 1%
1% of 540 = ?
Always divide the number by 100 to find 1%
540 ÷ 1 = 5.4
Ben and Sam have a bag containing 48 sweets. Whilst watching a film they eat 75% of the sweets. How many sweets are left?
There are 300 pupils in a school and 75% of the pupils are boys. How many girls are there in the school?