This is a simple slide presentation for teaching class 4 students in our country.

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Calculating with fractions
Fraction Mathematics in Primary Schools

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A
1
Contents
Calculating with fractions
Multiplying fractions

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Multiplying fractions by integers
We can illustrate this calculation on a number line:
0
1
4
1
4
1
4
1
2
1
4
3
4
1
4
1
1
4
1
4
1
1
4
1
2
1
1
4
3
4
1
1
4
2
1
4
What is 8 × ?

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Again, we can illustrate this calculation on a number line:
0
3
4
3
4
3
4
1
2
1
3
4
1
4
2
3
4
3
3
4
3
4
3
3
4
1
2
4
3
4
1
4
5
3
4
6
3
4
3
4
6
3
4
1
2
7
3
4
1
4
8
3
4
9
3
4
What is 12 × ?
Multiplying fractions by integers

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Let’s use a number line again:
0
1
3
1
3
1
3
2
3
1
3
1
1
3
1
3
1
1
3
2
3
1
1
3
2
1
3
1
3
2
1
3
2
3
2
1
3
3
1
3
What is 9 × ?
Multiplying fractions by integers

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So,
8 × = 21
4
12 × = 93
4
9 × = 31
3
What do
you notice?
What do
you notice?
and
Multiplying fractions by integers

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Following the rules of arithmetic, we know that,
8 ×
1
4
=
1
4
× 8
In maths the word ‘of’ (এর) means ‘times’ (গুণ).
=
1
4
of 8 = 8 ÷ 4
These are equivalent calculations.
Multiplying fractions by integers

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Means the same as:
3
5
20 ×
3
5
× 20
3
5
of 20
1
5
3 × of 20
20 × 3 ÷ 5 20 ÷ 5 × 3 3 ÷ 5 × 20
Equivalent calculations

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When we multiply a fraction by an integer we:
multiply by the numerator
and
divide by the denominator
For example,
4
9
54 × = 54 ÷ 9 × 4
= 6 × 4
= 24
Multiplying fractions by integers

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When we multiply by a fraction we:
multiply by the numerator
and
divide by the denominator
Multiplying fractions

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Exercise A Work out the following

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Presentation By
MD IMRAN HOSSAIN (010132)
Thank you all.