Many people think mental math is only for geniuses. The truth? A few simple tricks can make calculations much faster and easier. 1. Multiply by 10 Just add a zero. 25 × 10 = 250 2. Multiply by 11 For two-digit numbers, add the digits and place the answer between them. 34 × 11 = 374 (3 + 4 = 7) 3. Multiply by 5 Multiply by 10, then divide by 2. 48 × 5 = 480 ÷ 2 = 240 4. Find 15% Quickly Find 10%, then add half of it. 15% of 80: 10% = 8 5% = 4 Answer = 12 5. Square Numbers Ending in 5 Multiply the first digit(s) by the next number and add 25. 25² = 2 × 3 = 6 → 625 65² = 6 × 7 = 42 → 4225 6. Multiply by 9 Multiply by 10 and subtract the original number. 72 × 9 = 720 − 72 = 648 7. Double and Halve When multiplying, double one number and halve the other. 25 × 16 = 50 × 8 = 100 × 4 = 400 8. Check Answers with Digit Sums Add the digits of your answer repeatedly until one digit remains. This can help spot obvious mistakes. Mental math is not about memorizing difficult formulas. It is about recognizing patterns and using shortcuts that save time. The more you practice these tricks, the faster your brain becomes at handling everyday calculations without a calculator. How many of these tricks did you already know?
