Extending Hot Shots
I am learning to solve different kinds of percentage problems.
Do not start this lesson unless you have an excellent understanding of Hot Shots.
Percentage unknown
e.g. Tim scored 25
out of 30 in a test
what percentage did
he get correct?
25
= ?%
30
Part unknown
e.g. Susan completed
a test with 35
questions. She scored
60%. How many
questions did she get
correct?
?
= 60%
35
Whole unknown
e.g. Blake answered
20 questions correctly
in a test. That was a
score of 80%. How
many questions were
in the test?
20
= 80%
?
Percentage unknown
Use a calculator to help you with the division in this question.
Alice answered 32 quiz questions and got 24 correct. What percentage did
she answer correctly?
We can display this question on a number line.
Questions
0
24
32
0
?
75%
100% Answers
We could divide 100 by 32. This would tell us what percentage each question
is worth. 100 ÷ 32 = 3.125
Each mark is worth 3.125% and Alice answered 24 questions so… 24 X 3.125 = 75%
Or we could….
Divide 24 by 32.
24 ÷ 32 = ?0.75
This gives us the percentage as a decimal.
Part unknown
Use a calculator to help you with the division in this question.
Zoe answered 45 quiz questions and got 80% correct. How many
questions did she get correct?
We can display this question on a number line.
?
36
0
45
0
80%
Questions
100% Answers
We could divide 45 by 100. This would tell us what mark each percentage is
worth.
45 ÷ 100 = 0.45
Each percentage is worth 0.45 and Alice answered 80% correctly.
Or we could work out 80% of 45….
So… 0.8 X 45 = ?36
80% is the same as 0.8
80 X 0.45 = 36
Whole unknown
Use a calculator to help you with the division in this question.
Stacey answered 72 quiz questions correctly which was 90% correct. How
many questions were there?
We can display this question on a number line.
?
0
72
0
90%
Questions
100% Answers
We could divide 72 by 90. This works out how much of a mark each percentage
is. 72 ÷ 90 = ?
0.8
Each mark is worth 0.8 of a percentage.
100% is every question so…
100 X 0.8 = 80
Note: Whole unknown questions are much more difficult than the other two types
of questions we have looked at.
Now try these questions on your own.
You may use a calculator to help you answer the following questions.
Click again when you have worked out all your answers.
1) Tim threw a cricket ball at a wicket 25 times. He hit it 10 times.
What percentage of the time did he hit the wicket?
40%
2) Allan ate 75 pieces of fruit. 20% of these were bananas. How many
bananas did he eat?
15%
Need some more practise? Try Teacher Tools Fractions, Decimals and
Percentages Book Numeracy resources