Lesson 10 of 11
Track quiz
Show on a big screenEight ideas, eight checks. The table sits first, so you can look back.
| Idea | How it goes |
|---|---|
| Out of a hundred | Multiply both numbers by one amount. Stop when the second reads 100. |
| Three names | A fraction, a decimal and a percentage can name one amount. |
| Taking a percentage | To take a percentage of an amount, find pieces and add them. |
| Finding a percentage | Write the part over the whole. Divide. Then multiply by 100. |
| The base | A rise or a fall is a percentage of the base. |
| There and back | The second percentage is taken of the new amount, not the start. So an equal rise and fall do not cancel. |
| Comparing fairly | Compare shares, not counts. |
| Past a hundred | Name the whole first. The part can be bigger than the whole, then it is over 100%. |
A tray holds 20 seedlings. 13 have flowered. What percentage is that?
Which percentage is 1/5?
What is 15% of 60?
You score 18 out of 24. What percentage is that?
A ₹800 bag of rice has 25% off. What do you pay?
A ₹400 fare rises 10%, then falls 10%. What is it now?
Class A got 12 of 15 sums right. Class B got 32 of 50. Which class did better?
A stall sold ₹400 on Friday and ₹1,000 on Saturday. Saturday is what percentage of Friday?
Part II, Chapter 1 is Fractions in Disguise. Go and read it there.
Next: The Baudhayana-Pythagoras Theorem. A square is drawn on each side of a triangle. One angle makes them fit.
Reveal every answer to finish this lesson.