Multiply by 5, 25 and 50 in seconds — the halving trick most people don't know
48 × 25. Most people set up long multiplication. The halving method: divide 48 by 4, multiply by 100. Answer: 1,200, in about 3 seconds. This is the most useful everyday Vedic shortcut because these numbers — 5, 25, 50 — appear constantly.
What's 48 × 25? Give yourself 10 seconds using the method you were taught in school. Now try this: 48 divided by 4 is 12. 12 times 100 is 1,200. Done. Under 3 seconds.
The multiply by 25 trick — and its cousins for 5 and 50 — convert multiplication problems into halving problems. Halving is faster than multiplying because it involves one operation on a number you already have, rather than a multi-step procedure. Once you know which halving step corresponds to which multiplier, these calculations take as long as moving a decimal point.
These three multipliers appear constantly in everyday life: prices, percentages, discounts, recipes, split bills. This is the Vedic technique with the highest immediate practical return.
The three rules
× 5 = divide by 2, then × 10
× 25 = divide by 4, then × 100
× 50 = divide by 2, then × 100
×5
Halve the number, then shift one decimal place. Odd numbers get a .5 mid-step — handle it by multiplying the half by 10.
48 × 5
Halve: 48 ÷ 2 = 24
Shift: 24 × 10 = 240
37 × 5
Halve: 37 ÷ 2 = 18.5
Shift: 18.5 × 10 = 185
For odd numbers: last digit of answer is always 5.
×25
Divide by 4, then shift two decimal places. If divisible by 4, one clean step. If not, halve twice.
36 × 25
Quarter: 36 ÷ 4 = 9
Shift: 9 × 100 = 900
48 × 25
Quarter: 48 ÷ 4 = 12
Shift: 12 × 100 = 1,200
Check: 48 × 25 = 48 × 100 ÷ 4 = 4,800 ÷ 4 = 1,200 ✓
×50
Halve the number, then shift two decimal places — like ×25 but one halving instead of two.
78 × 50
Halve: 78 ÷ 2 = 39
Shift: 39 × 100 = 3,900
66 × 50
Halve: 66 ÷ 2 = 33
Shift: 33 × 100 = 3,300
Challenge
Larger numbers — same rules, more zeros to shift.
124 × 25
Quarter: 124 ÷ 4 = 31
Shift: 31 × 100 = 3,100
246 × 50
Halve: 246 ÷ 2 = 123
Shift: 123 × 100 = 12,300
See the halving logic in motion
The diagram below shows how 48 × 25 reduces to a single halving and a decimal shift.
[Interactive visual flow available at https://www.thevedicmind.com/blog/multiply-by-5-25-50-trick.]
How halving replaces multiplication — the arithmetic behind the trick
These shortcuts work because 5, 25, and 50 are all fractions of powers of 10:
5 = 10 ÷ 2 so n × 5 = (n ÷ 2) × 10
25 = 100 ÷ 4 so n × 25 = (n ÷ 4) × 100
50 = 100 ÷ 2 so n × 50 = (n ÷ 2) × 100
Dividing by 2 or 4 is trivial for the brain. Multiplying by 10 or 100 is just appending zeros. So the hard multiplication gets replaced by two easy operations. The Vedic sutra here is Anurupyena — "proportionality" — using the relationship between numbers rather than computing them directly.
The same principle extends to ×125 (divide by 8, times 1000), ×250 (divide by 4, times 1000), and ×500 (divide by 2, times 1000). Once you see the pattern, every multiplier that's a power of 5 becomes a halving problem. For the percentage version of this same idea, see the percentage flip trick.
Use this today
Next time you see a 25% discount on something, calculate the discounted price mentally before reading the tag. Price is £48. 25% of 48: 48 ÷ 4 = 12. You save £12. £36 final price. Before you finish reading the sticker. That's the technique working in the real world.
See your Vedic Math level → — Free 60-second quiz. No signup required.
https://www.thevedicmind.com/quiz