eZine · Nigerian exams
Fractions, decimals, approximations and percentages
JAMB Mathematics topic guide with 2 practice questions.
What to revise
- fractions and decimals
- significant figures
- decimal places
- percentage errors
- simple interest
- profit and loss percent
- ratio, proportion and rate
- shares and value added tax (VAT)
You should be able to
- perform basic operations on fractions and decimals
- express to a specified number of significant figures and decimal places
- calculate simple interest, profit and loss per cent, ratio, proportion, rate and percentage error
- solve problems involving shares and VAT
From JAMB's Mathematics syllabus official. Full syllabus →
eZine's published bank has 21 questions on this topic (counted 29 October 2026).
Practice questions
Question 1 · Fractions, decimals, approximations and percentages
Find the simple interest on ₦45 000 for 3 years at 8% per annum.
Show answer and explanation
Answer: B. ₦10 800
I = PRT/100 = 45 000 × 8 × 3 / 100 = ₦10 800. The answer is ₦10 800. Why the other options are wrong: ₦55 800 — this is the amount (principal + interest), not the interest. ₦3 600 — this is the interest for one year only. ₦1 080 — it divides by 1000 instead of 100.
eZine practice question (original, teacher-reviewed)
Question 2 · Fractions, decimals, approximations and percentages
Emeka sold a phone for ₦34 200 at a loss of 5%. What did he pay for the phone?
Show answer and explanation
Answer: A. ₦36 000
Selling at a 5% loss means SP = 95% of CP. CP = 34 200 ÷ 0.95 = ₦36 000. The answer is ₦36 000. Why the other options are wrong: ₦35 910 — it adds 5% of the selling price; the 5% is a percentage of the cost price. ₦32 490 — it takes 5% off the selling price, which would make the cost lower than the selling price. ₦36 200 — it adds a guessed ₦2 000 rather than solving 0.95 × CP = 34 200.
eZine practice question (original, teacher-reviewed)
Practise more Fractions, decimals, approximations and percentages questions with explanations.
Practise free →