Harder fractions of amounts Example: Hassan has 20 pencils. He lends pencils does Hassan lend? To find 1 4 1 4
3 4
we need to find
to his friends. How many
first.
of 20 = 20 รท 4 = 5 = of 20 = 5
We know that So 3 4
1 4
3 4
3 4
3 4
=
1 4
+
1 4
+
1 4
of 20 = 5 + 5 + 5
= of 20 = 15
A shorter way of showing this calculation is to divide the amount by the denominator (in blue) and then multiply by the numerator (in red). 3 4
of 20
20 รท 4 = 5 5 ร 3 = 15 3 4
of 20 = 15
Warm up 1
Find
3 4
of these amounts.
a) 12 b) 16 c) 24 2
Find
2 3
of these amounts.
a) 9 b) 18 c) 12 3
Find
3 5
a) 25 b) 15 c) 45
10
of these amounts.