← Back to Class 5🔒
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Class 5 · Topic 16
Commercial Maths & Proportion
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Step 1 · Learn
Read the ideas
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Percentage
Fraction × 100 = percentage. % ÷ 100 = fraction.
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Unitary Method
Divide for one, multiply for many.
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Percentage of a Quantity
Convert % to fraction, then multiply.
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Ratio & Proportion
Simplify by hcf. Cross-multiply to check proportions.
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Speed, Distance & Time
Triangle trick: cover the unknown, read the formula.
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Simple Interest
si = (P × R × T) ÷ 100. Per year.
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Counting Principle
M ways × N ways = M × N total combos. Always multiply, never add.
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Step 2 · Practice
Try the quests
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Step 3 · Boss Battle
Beat the boss
🛡️ 🛡️ 🛡️ 3 shields — lose all → 60-second cooldown
Round 1
Percentage
🔒Round 2
Unitary Method
🔒Round 3
Percentage of a Quantity
🔒Round 4
Ratio & Proportion
🔒Round 5
Speed, Distance & Time
🔒Round 6
Simple Interest
🔒Round 7
Counting Principle
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