Vertical Addition by Partition with 2-digit Numbers 54 + 66 110 (50 + 60) Add the tens 10 (4 + 6) Add the units 120 Vertical Addition by Partition with 3-digit Numbers 770 + 807 1500 (700 + 800) Add the hundreds 70 (70 + 0) Add the tens 7 (0 + 7) Add the units 1577 |