Money (Copy)

Money Calculations Cheat Sheet (IGCSE Mathematics 0580)

1. Calculate with Money

• Addition & Subtraction:
  Use standard methods to add or subtract amounts in the same currency.
  Always line up decimal points.
• Multiplication:
  Used when calculating total cost of multiple items.
  Total Cost = Number of items × Price per item
• Division:
  Used to find unit price or how much each person pays when sharing.
  Unit Price = Total Cost ÷ Quantity
• Examples:
  • 5 pens cost ₨32 each → Total = 5 × 32 = ₨160
  • ₨480 shared between 4 people → ₨480 ÷ 4 = ₨120 each
• Working with Decimal Values:
  Money values may involve decimals: e.g., ₨47.50 + ₨25.75 = ₨73.25
  Always round final answers to 2 decimal places unless stated otherwise.
• Profit and Loss Calculations:
  • Profit = Selling Price – Cost Price
  • Loss = Cost Price – Selling Price
  • %Profit or %Loss = (Profit or Loss ÷ Cost Price) × 100
• Discounts & Sale Prices:
  • Discount = (Discount % × Original Price) ÷ 100
  • Sale Price = Original Price – Discount
• VAT or Tax Calculations:
  • VAT = (Rate × Price) ÷ 100
  • Final Price = Original Price + VAT
• Interest (Simple only):
  • Interest = (Principal × Rate × Time) ÷ 100

2. Currency Conversion

• Formula:
  Amount in New Currency = Amount in Old Currency × Exchange Rate
• Reverse Conversion:
  Amount in Old Currency = Amount in New Currency ÷ Exchange Rate
• Example:
  • Exchange rate: $1 = ₨280
  • ₨14,000 to USD → 14,000 ÷ 280 = $50
  • $75 to PKR → 75 × 280 = ₨21,000
• Key Tips:
  • Always check the direction of conversion (from or to foreign currency)
  • Write unit rates clearly before using them (e.g., 1 USD = 280 PKR)
  • Round your final answer to 2 decimal places unless instructed otherwise
  • In exams, look for “Buy” and “Sell” rates in tables – choose correctly depending on context:
    • Buy rate – when converting foreign currency to local
    • Sell rate – when converting local currency to foreign

Practical Applications in Exams:

• Total cost of multiple items
• Calculating change given to a customer
• Profit/loss scenarios in business contexts
• Travel-related conversions (e.g., converting local money to USD/Euro)
• Applying percentage discounts, tax or VAT
• Budgeting and comparing prices between currencies

Common Currency Abbreviations

Note: Currency values may fluctuate – in real-world problems, always use the exchange rate provided in the question.