Percentages Help: Why Your Child Keeps Getting Stuck (And What Actually Works)

Ten per cent of a number comes back from your child without a pause. Ask what a jacket cost before a 20% sale took it down to £48 and you get silence, or £57.60.

I'm Aadam. I have taught percentages to several hundred 11+ and GCSE students at SHLC. Most children who struggle here own one method and one direction, and the exam asks for several of both.

The real problem isn't finding 10%

Two things account for most lost marks here, and neither is arithmetic.

Only knowing how to go forwards. Find 20% of 60 and your child is fine. Tell them 20% of a number is 12 and ask for the number, and the same child multiplies instead of divides. They know how to walk from the whole to the part and have never been shown the walk back.

Not knowing what 100% refers to. In a sale question, 100% is the original price. In a percentage change question, 100% is the amount you started with, which is not always the first number in the sentence. A child who does not ask what 100% means here will pick the wrong number to work from and every step afterwards is wasted.

This is also why increasing by 20% and then decreasing by 20% does not take you back to where you started. The second 20% is a percentage of a different number. Most children find that surprising, and surprise is a good moment to teach.

Why worksheets alone don't fix it

A percentages worksheet gives twenty questions that all run in the same direction, so a child can complete the whole page with one method and feel confident. Then the paper asks for the original price and the method they practised twenty times does not apply.

Percentages also sit on top of fractions and decimals, so a shaky child carries two problems into one question. Finding 15% of 240 in your head means knowing that 10% is a tenth and 5% is half of that. When tenths wobble, the percentage looks like the difficulty.

The percentage skills that trip children up, in order

Reverse percentages fall apart for children who never got comfortable building 35% out of smaller pieces, so work down this list rather than into it.

1. Percentage as a number out of 100. Linked to the fraction and the decimal for the same amount, so all three are one idea rather than three.

2. Building any percentage from 10%, 5% and 1%. Finding 35% by taking three tens and a five. This is the method that works without a calculator, which is most of the 11+ paper.

3. Using a multiplier. Finding 65% by multiplying by 0.65, which is faster and is the method that makes reverse questions possible later.

4. Increase and decrease. Both by finding the change and adding it on, and by going straight there with a single multiplier.

5. Writing one number as a percentage of another. Scoring 34 out of 40, deciding which number goes underneath, then converting.

6. Percentage change. The change divided by the original amount, and knowing which of the two numbers in the question is the original.

7. Reverse percentages. Given the price after a change, finding the price before it. Dividing by the multiplier rather than taking the same percentage off again.

8. Repeated and multi step change. Two changes one after the other, including the case where they cancel out to something other than zero.

What actually closes the gap

Three habits, none of which take long to build.

Ask what 100% is before doing anything else. Have your child write that question at the top of the working. If 100% is the original price, your child knows immediately that the number in the question is not it, and the reverse method follows naturally.

Build percentages from parts your child already owns. 10%, then 5%, then 1%. A child who can produce those three from any number can build 17.5% or 43% without a calculator, and a non calculator paper is no longer a problem.

Show the two directions side by side. Work out 80% of 60 and get 48. Then start from 48 and get back to 60. Doing both on the same numbers in one sitting is what connects them.

The lessons we built to fix this

Our Percentages Bundle teaches the three directions in the order above. Three interactive lessons, 15 units, 262 questions.

Percentages of Amounts covers percentage as a fraction and a decimal, building any percentage from 10%, 5% and 1%, and the multiplier method.

Percentage Increase, Decrease and Change covers increase and decrease both ways, writing one number as a percentage of another, and percentage change including profit and loss.

Reverse Percentages covers finding the original amount after an increase or a decrease, and the multi step questions that combine both.

Every lesson starts by walking your child through one question, a line at a time, before asking for anything back. Answers sit hidden behind a click, so guessing and checking is not an option. The question tiers go up in steps, so a child does not start at the deep end.

If fractions and decimals need work too, all three sit together inside The Complete 11+ Maths Course, taught in the order that makes each one easier than the last.

What to do this week

Try these two before you buy anything.

Ask your child for 10% of 60, then 5% of 60, then 1% of 60. If all three come back quickly, ask for 17% and watch whether they build it from the parts.

Then ask them this: a coat is £48 in a sale after 20% off. What was it before? If the answer is £57.60, they have added 20% back on instead of working out what 80% of the original was. Work on that before anything else.

Our free percentages practice page has more questions you can use tonight at no cost, and each one names the lesson it comes from, so you can see where the work is needed.

For the whole sequence taught in order, the Percentages Bundle covers it end to end, or pick up the single lesson your child is stuck on. For a second opinion on where your child actually stands, book a free consultation and we will go through it.

Aadam, SHLC Tutors