Junior Cycle · Financial Maths ⏱ Tested in 3 exam questions since 2023 Lesson 1 of 7

JCHL Financial Maths 1: Percentages, Mark up, Margin

This tutorial is for members

Read the lesson notes free below — subscribe to watch the full worked video and download the PDF.

Subscribe for full access · €199/yr

You’ll learn

  • Percentage error = error/(actual value) × 100 — the actual value goes on the bottom, not the estimate
  • Mark up = profit/(cost price) × 100
  • Margin = profit/(selling price) × 100
  • Profit = selling price − cost price
  • Finding the original: if an amount is, say, 90% of the original, divide by 90 and × 100 to get 100% (the original)

Formula used

percentage error = error/(actual value) × 100

mark up = profit/(cost price) × 100

margin = profit/(selling price) × 100

profit = selling price - cost price

MUST LEARN

Most recent exam questions

  • 2025 Q1(b)
  • 2024 Q4(b)
  • 2023 Q2(e)

💬 Stuck on something in this lesson?

Send your question with this lesson’s name attached — you’ll get a reply by email.