Cost price, selling price and marked price; profit and loss as amounts and percentages; discount; mark-up; sales tax; and working backwards to the original price.
5 narrated scenes. Press play, listen and read along — the points appear as they are explained. Use ‹ Prev / Next › or the scene bar to jump to any scene.
Every shop, every sale, every bill — consumer arithmetic is the most “real-life” maths in the syllabus, and it is worth marks in every Paper 02.
Narration uses your device’s built-in voice. No sound? Switch to “Captions only” — the captions advance on their own.
Copy these into your notebook in your own words — that is how they stick.
Profit = SP − CP. Loss = CP − SP.
(profit or loss ÷ cost price) × 100. Always the COST price.
Discount = % × marked price. Sale price = marked price − discount (or × (1 − r/100)).
SP = CP × (1 + mark-up %/100). Mark-up is a % of the cost price.
Price with tax = price × (1 + r/100). Tax = r% × price before tax.
Divide by the multiplier: ÷ 0.8 (after 20% off), ÷ 1.15 (including 15% tax).
Find the dollar profit / loss / discount first, then convert to a percentage.
A discount lowers the price; a mark-up or tax raises it. Check the direction.
3 quick games on this lesson. Earn XP and badges as you play — your best score for each game is saved. Games are for practice and do not change your exam readiness. More games in the Mathematics Arcade.
8 items modelled on real CSEC Paper 1 questions. Choose one answer for each, then check. Aim for 80% or better. Work each item on paper first.
Write full answers, then reveal the mark scheme and tick the points you earned (16 marks in total). Show all your working — method marks count. Your answers are saved on this device.
Question 1 [9 marks]
A shopkeeper sold 12 boxes of juice at $3.34 each. His total profit on the boxes was $11.88.
(a) Show that the cost price of one box of juice was $2.35. [3]
(b) Calculate the percentage profit on each box, correct to 1 decimal place. [2]
(c) At a sale he reduces the selling price by 15%. Calculate the new selling price of one box. [2]
(d) Does he still make a profit at the sale price? Justify your answer. [2]
Question 2 [7 marks]
A laptop is marked at $2 400. In a sale the shop offers a 15% discount. Sales tax of 12.5% is then added to the sale price.
(a) Calculate the amount of the discount. [1]
(b) Calculate the sale price before tax. [1]
(c) Calculate the total amount a customer pays, including tax. [2]
(d) The shop bought the laptop for $1 800. Calculate its percentage profit on the sale price before tax. [3]
Find these in your own past-paper booklets for extra timed practice. Items above are written in the style of these papers; any adapted from a specific question say so.