Percentages

For grown-ups: this lesson in words

Years 5 and 6 · Maths

Percentages: I can say what per cent means and find percentages of amounts.

1. Here are 100 counters: 10 rows of 10. Per cent means out of every 100.

   Split off 1 column. That is 10 counters out of 100.

   10 out of 100 = 10/100 = 10%. We write per cent with the sign %.

   The other side has 10 rows of 9: 90 counters. 90 out of 100 = 90%

   Picture: An array of 10 rows of 10 counters. A gap splits it after 1 column, into 10 rows of 1 counter and 10 rows of 9 counters.

2. This square is cut into 10 equal strips. Each strip is 10% of the square.

   3 strips are shaded: 10%, 20%, 30%.

   30% = 30/100 = 0.3

   Picture: A square cut into 10 equal parts, with 3 parts shaded. It is labelled 30%.

3. Your turn: This square has 10 equal strips, and 7 are shaded. Each strip is 10%. What percentage of the square is shaded?

   Picture: A square cut into 10 equal parts, with 7 parts shaded.

   Choose one:

   • 7%
   • 30%
   • 70%

   Answer

   The answer: 70%

   7 strips of 10% make 70%. 70% = 70/100 = 0.7

   Picture: A square cut into 10 equal parts, with 7 parts shaded. It is labelled 70%.

Words to know

per cent:

Out of every 100. 1% is 1 out of 100.

percentage:

A number of parts out of 100, written with the % sign.

hundredth:

One of 100 equal parts. 1 hundredth is 1/100, or 0.01.

equivalent:

Worth the same, like 1/2, 50% and 0.5.