P5 Maths: Percentages (1) - Understanding Percent (Paper 4 (error Clinic))

P5 Maths: Percentages (1) – Understanding Percent (Paper 4 (error clinic))

2026-11-15

Tutor Prep Guide · What a percentage means (parts per hundred), converting between percentages and fractions, converting between percentages and decimals, finding a percentage of a quantity, comparing sizes and common place-value slips

P5 Maths: Percentages (1) – Understanding Percent (Paper 4 (error clinic))

Ten introductory percentage questions on what a percentage means, converting to and from fractions and decimals, finding a percentage of a quantity and comparing sizes, with answers and one-line notes.

Level: Primary 5 Maths; format: meaning of percent, converting percentages to and from fractions and decimals, finding a percentage of a quantity, comparing sizes, increases and decreases, and error diagnosis.　Primary 5 percentage practice: ten questions on the meaning of percent, converting to and from fractions and decimals, finding a percentage of a quantity, comparing sizes, simple increases and decreases, and common place-value slips, each with an answer and a one-line note.

01　Paper details (check answers afterwards)

Item	Detail
Questions	10
Suggested time	20
Difficulty mix	Foundation 3 · Intermediate 3 · Challenge 3 · Error redo 1
Chapter	Chapter: P5 Maths: Percentages (1) – Understanding Percent
Level	P5

02　Questions (10 items)

FoundationA student writes 0.4 as 4%. What is wrong?
FoundationA student works out 8% of 300 as 300 x 8 = 2400. What is the correct answer?
FoundationWhat is 30% plus 40%?
IntermediateAn item costing 200 dollars is sold at 15% off. How much is taken off?
IntermediateWhich is larger, 5% or 0.5%, and what is 0.5% as a decimal?
IntermediateA number falls 25% and then rises 25%. What percentage of the original is left?
ChallengeA deposit of 2000 dollars earns 3% a year. What is the interest for one year?
ChallengeA class of 40 has 60% girls. How many girls are there?
ChallengeAn item costing 500 dollars is sold at 30% off. What is the selling price?
Error redoA student treats 120% as 1.2%. What is the correct value?

03　Answers and one-line notes

#	Answer	One-line note
1	0.4 x 100 = 40, so 0.4 is 40%; 4% is actually the decimal 0.04.	To change a decimal to a percentage multiply by 100, moving the point two places; 4% and 0.4 differ tenfold.
2	24.	Write 8% as 0.08 first: 300 x 0.08 = 24; multiplying by 8 makes it a hundred times too big.
3	70%.	Percentages of the same whole add directly: 30% + 40% = 70%, that is 0.3 + 0.4 = 0.7.
4	30 dollars.	A 15% discount takes off 200 x 0.15 = 30, so the price becomes 170 dollars.
5	5% is larger; 0.5% is 0.005.	5% is 0.05 while 0.5% is 0.005, a tenfold gap; never overlook the decimal point before a percent sign.
6	93.75%.	Start from 100: 100 x 0.75 = 75 and 75 x 1.25 = 93.75; the two percentages use different bases.
7	60 dollars.	2000 x 0.03 = 60; the interest is three per cent of the principal.
8	24.	40 x 0.6 = 24 girls, leaving 16 boys, and the two add to 40.
9	350 dollars.	A 30% discount means paying 70%: 500 x 0.7 = 350, with 150 dollars off.
10	120% = 1.2; 1.2% is only 0.012, a hundred times smaller.	The percent sign means divide by 100: 120 / 100 = 1.2, while writing 1.2% shrinks every result a hundredfold.

04　What to do after marking

After marking, redo only the wrong items and write down which step went wrong (formula, unit, or misread number).
Repeat the same item two days later; move to the next paper only when both attempts are correct.
Parents only need the answer and note columns; there is no need to explain every item.

Ask first what whole a percentage is taken from. When the question says “of”, multiply; when it asks what fraction one value is of another, divide the part by the whole. The percent sign is notation only, so the decimal is what does the work. Convert to decimals or fractions before comparing, and multiply step by step for two successive changes instead of adding the percentages.Tutor Registration →

Questions and answers are written originally by the TutorZone team and are not taken from any school, publisher or examination authority paper. Every value is checked by computer.