Lattice method
Helps keep carrying tidy: every digit product gets its own box, and you only add at the end.
Step 1Write 7 across the top and 12 down the right side, one digit per box.
Step 2Multiply each pair of digits. Put the tens above the diagonal and the ones below it.
- 1 × 7 = 7 → tens 0, ones 7
- 2 × 7 = 14 → tens 1, ones 4
Step 3Add along each diagonal, starting at the bottom right. Carry when a sum is 10 or more.
- Diagonal 1 (from the bottom right): 4 = 4
- Diagonal 2 (from the bottom right): 8 = 8
- Diagonal 3 (from the bottom right): 0 = 0
Step 4Read the digits down the left side and along the bottom: 8 4. So 7 × 12 = 84.