Step 1 of 4 · The trick
Subtract 1,000? Only the thousands digit moves.
Each digit sits in its own column:
K · H · T · O
Subtract 1,000 → only the thousands digit changes.
All other columns stay exactly the same.
3,456 − 1,000 → thousands: 3 − 1 = 2, rest stays → 2,456
Step 2 of 4 · 3,456 − 1,000
3,456 − 1,000 = ?
aligned to the thousands column ↑
3
−
1
=
2
3,456 − 1,000 = 2,456
Step 3 of 4 · 1,500 − 1,000 (zero on top!)
1,500 − 1,000 = ?
aligned to the thousands column ↑
1
−
1
=
0
1,500 − 1,000 = 500