10.1 Fractions, decimals and percentages · Unit 10 Percentages

1 · Teaching slidesuse ← → keys

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2 · Key words

per centOut of a hundred.

percentageA number written as a part of 100.

equivalentThe same value written in a different form.

convertChange from one form to another.

simplest formA fraction with no common factor except 1.

3 · Summary of the sectionrevise from this

Per cent means out of a hundred. 45% is 45 out of every 100.
Percentage → decimal: divide by 100. 35% = 0.35.
Decimal → percentage: multiply by 100. 0.35 = 35%.
Percentage → fraction: put it over 100 and simplify. 45% = 45/100 = 9/20.
Fraction → percentage: divide, then multiply by 100. 3/8 = 0.375 = 37.5%.
Learn the common ones by heart: 1/2, 1/4, 3/4, 1/5, 1/10, 1/8.
To compare, convert everything to one form — percentages are usually easiest.
A percentage can be more than 100. 150% of 20 is 30.

PDFPrintable worksheet All 72 questions, space to work PDFWorked answers Full solutions, not just the answer

Video lessons2 videos

Math Antics - What Are Percentages?

American mathantics

Where “per cent” comes from, and why the denominator is always 100.

Math Antics - Percents And Equivalent Fractions

American mathantics

Moving between percentages, fractions and decimals with confidence.

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Fractions, decimals and percentages