Vertical Addition by Partition with 2-digit Numbers 44 + 43 80 (40 + 40) Add the tens 7 (4 + 3) Add the units 87 Vertical Addition by Partition with 3-digit Numbers 628 + 520 1100 (600 + 500) Add the hundreds 40 (20 + 20) Add the tens 8 (8 + 0) Add the units 1148 |