Vertical Addition by Partition with 2-digit Numbers 74 + 55 120 (70 + 50) Add the tens 9 (4 + 5) Add the units 129 Vertical Addition by Partition with 3-digit Numbers 261 + 135 300 (200 + 100) Add the hundreds 90 (60 + 30) Add the tens 6 (1 + 5) Add the units 396 |