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Interchanging. Fractions, Decimals and Percentages. What area is shaded?. Answers. 0.5. 1/2. ?. Fraction: Percentage : Decimal:. ?. 50%. ?. All 3 numbers mean the same thing. Interchanging. Fractions, decimals and percentages can all be used to describe parts of a whole.
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Interchanging Fractions, Decimals and Percentages
Answers 0.5 1/2 ? Fraction: Percentage: Decimal: ? 50% ? All 3 numbers mean the same thing.
Interchanging • Fractions, decimals and percentages can all be used to describe parts of a whole. • It is therefore possible to interchange them.
More shapes Here are some more shaded shapes. Can you describe the shaded areas using fractions, percentages and decimals?
Can you name the Fraction. Percentage & Decimal? 0.25 F: P: D: 1/4 ? ? 25% ?
Can you name the Fraction, Percentage & Decimal? 0.3 F: P: D: 3/10 ? ? 30% ?
Can you name the Fraction. Percentage & Decimal? 0.24 F: P: D: 6/25 ? ? 24% ?
Interchanging Without Pictures
Interchanging • You don’t need a picture to interchange Fractions, Decimals & Percentages. • There are calculations that will do the job quickly and easily.
Interchanging Decimals & Percentages
Decimals & Percentages • Percentages are a measure out of 100. • Decimals are a measure out of 1. • To change a decimal into a percentage you multiply by 100. • To change a percentage into a decimal you divide by 100.
x 100 Decimals Percentages 100 The diagram illustrates this.
0.45 = 0.67 = 0.12 = 0.30 = 45% 67% 12% 30% Decimals to Percentages
10% = 5% = 11.1% = 888% = 0.1 0.05 0.111 8.88 Percentages to Decimals
Interchanging Percentages to Fractions
Percentages to Fractions • A percentage is already a type of fraction. • To be precise, a percentage is a fraction of one hundred. • To change a percentage into a fraction, you first put the percentage over 100, then simplify.
20 = = 60% 100 Here is an example ? 60 ? 3 20 = ? 5
10 = = 70% 100 Now try this one. ? 70 ? 7 10 = 10 ?
10% = 80% = 22% = 15% = 7% = 98% = 48% = 1/10 4/5 11/50 3/20 7/100 49/50 12/25 Try working out these.
Interchanging Fractions to Decimals
Fractions to Decimals • You might not realise it, but a fraction is actually a division sum! • For example the fraction ¾ is the division sum 3 4. • When you do the sum you get the decimal. • The only tricky bit is doing the sum.
3 = 4 4 3 ¾ as a decimal.
3 . 4 3 . 0 0 So how many 4s go into 3? 0 remainder 3 0 = 3 4
3 . 4 3 . 0 0 How many 4’s in 30? 7 remainder 2 0 7 = 3 2 4
3 0 . 7 5 = 3 2 4 4 3 . 0 0 The answer … 0.75
1/2 = 1/4 = 1/5 = 3/10 = 4/5 = 9/10 = 1/8 = 0.5 0.25 0.2 0.3 0.8 0.9 0.125 Try these
Interchanging Fractions, Decimals & Percentages By S. Howarth • ORB Education Visit http://www.orbeducation.com for a range of quality teaching materials.