To find a percentage of a whole, write the percentage over 100 and times the whole. And to turn a part into a percentage, write the part over the whole and times 100 percent. In the lesson. And to turn a part into a percentage, write the part over the whole and times one hundred percent.
Lesson video, with the working
Finding a percentage of a quantity
2 min 53 s
The film teaches 2 questions in turn. Each question shows first; its working is written as the film explains it.
A stall sold 400 chicken rice sets in one month. 40% of them were takeaway orders. How many of the sets were takeaway orders?
40% of 400 is 160 sets.
Ans: 160
Example 1
Out of the same 400 sets, 100 were sold on a Sunday. What percentage of the sets is that?
25% of the sets were sold on the Sunday.
Ans: 25%
How to solve it
Draw the whole as one bar. The whole is always 100 percent: here it is 400 sets.
To find a percentage of the whole, write the percentage over 100, then multiply by the whole: 40 over 100 times 400.
Cancel: 100 goes into 400 four times, so it becomes 40 times 4, which is 160 sets.
To turn a part into a percentage, write the part over the whole: 100 over 400.
Multiply by 100 percent: 100 over 400 times 100 percent is 25 percent.
To find a percentage of a whole, write the percentage over 100 and times the whole. And to turn a part into a percentage, write the part over the whole and times 100 percent.
Practice questions with worked solutions
Question 1 is free to try. The other question opens in the free trial, each with its full working.
How do you solve percentage of a quantity questions in P6?
Finding a percentage of a quantity is the everyday skill behind spending, saving and sales.
What your child learns here
Finding a percentage of a quantity is the everyday skill behind spending, saving and sales. This page revises the method from the year before and adds the Primary 6 twist, where a second percentage is taken of what remains, not of the starting amount.
Find a percentage of a whole by writing the percentage over 100 and multiplying by the whole.
Tell 'a percentage of' apart from 'as a percentage of', which puts the part over the whole.
Find a percentage of the remainder after a first amount has been taken.
Work backwards from what is left to the amount at the start.
Does the answer make sense?
Taking a percentage under 100% of an amount must give less than that amount, so 8% of 400 shuttlecocks must be fewer than a tenth of them. When your child works backwards from the money left after two purchases, the sum at the start must be bigger than the $1540 Mrs Rahim had left.
How to practise these questions
The Basic question here finds a percentage of a whole amount, turning the percentage into a fraction of a hundred and taking that share. If a percentage of a quantity is unclear, read the written step-by-step solution.
Questions parents ask
What is the quickest way to find a percentage of an amount? Write the percentage over 100 and multiply by the amount, cancelling first. For simple percentages, finding 10% or 1% first and scaling up works just as well.
What is the difference between 'percentage of' and 'as a percentage of'? '20% of 50' asks for an amount, which is 10. '10 as a percentage of 50' asks for a percentage, which is 20%. The first multiplies; the second puts the part over the whole.
Is percentage of a quantity a Primary 6 topic? Finding a percentage part of a whole is first taught the year before. In Primary 6 it returns with a second step, such as a percentage of what is left, and alongside finding the whole from a part.
