Lighten heavy arithmetic
Subtract from 100, 1000 or 10000 in one sweep
Borrowing across a row of zeros is the classic place careless mistakes creep in.
Spot it when
You are taking a number away from a clean power of 10 (making change, finding a complement).
Worked examples
The method builds the answer directly — worked results:
When you’ll actually hit this
Real moments — exams, homework, competitions — where this shortcut earns its keep.
You hand over ₹1000 for a ₹576 bill and want to check the change instantly.
All from 9 and the last from 10: 4, 2, 4 → 424, no borrowing.
A subtraction across many zeros, 10000 − 2345, in a timed arithmetic set.
Each digit from 9, last from 10 → 7655 in one pass.
Finding the deficiency of a number for a Nikhilam multiplication mid-working.
From 100: all-from-9-last-from-10 gives 12 — the deficiency you need.
The method behind it
निखिलं नवतश्चरमं दशतः
Nikhilaṃ Navataścaramaṃ Daśataḥ
“All from 9 and the last from 10”
Find how far each number is from the nearest power of 10. Those distances do the multiplication for you.
via long multiplication (12 partial products).
deficiencies 3 and 6, left=, right= (3 steps).
Use when
- • Both numbers within 10–15% of a power of 10 (10, 100, 1000)
Avoid when
- • Numbers far from any base (use Urdhva-Tiryakbyham)