Class 8 Math: Comparing Quantities Quick Revision Chapter Summary

Need to review the entire chapter before a test? This quick revision guide summarizes all the core concepts, topics, and equations taught in Class 8 Comparing Quantities to help you refresh your memory instantly.

Core Topics At a Glance

### 📌 Ratios and Percentages review Ratios compare two quantities. Percentages compare quantities relative to 100.

### 📌 Finding increase/decrease percent Percentage change measures the relative increase or decrease of a quantity relative to its initial value.

### 📌 Discounts and Markups Discount is the reduction in the Marked Price (MP) of an item. Markup is the increase added to the Cost Price.

### 📌 Sales tax, VAT, and GST bills Sales tax, VAT, and GST are government taxes added to the selling price of items, paid by the buyer.

### 📌 Compound Interest formula and APY Compound interest is calculated on the principal and the interest accumulated over previous periods.

### 📌 Compounding half-yearly When compounding half-yearly, interest is calculated twice a year. The rate is halved, and the compounding periods are doubled.

Key Formulas Mind Map

• Compound Interest Amount: `A = P\left(1 + \frac{R}{100}\right)^n` - Future accumulated value under annual compounding interest....

Revision Checklist

1. Review the subtopic guides and outline notes.
2. Practice writing the key formulas from memory.
3. Solve at least 3 worked examples and check your steps.
4. Take a timed practice quiz to verify your speed.