Adding

Formal Written Method Partitioning Vertically 2 3 7 8 2 3 7 8 + 1 1 4 9 + 1 1 4 9 3 5 2 1 7 1 3 0 0 0 4 0 0 1 1 0 1 7 3 5 2 7

Formal Written Method Partitioning Vertically 4 5 7 8 4 5 7 8 + 2 3 4 9 + 2 3 4 9 6 9 2 1 7 1 6 0 0 0 8 0 0 1 1 0 1 7 6 9 2 7

Formal Written Method Partitioning Vertically 4 6 8 7 4 6 8 7 + 5 7 4 9 + 5 7 4 9 1 0 4 1 3 1 6 1 9 0 0 0 1 3 0 0 1 2 0 1 6 1 0 4 3 6

Subtracting

Subtraction by adding on. 502 - 198 = 304 502 - 198 +2 +300 +2 2 (to 200) 300 (to 500) 198 200 500 502 2 (to 502) 304

Subtraction by adding on. 613 - 279 = 334 613 - 279 +1 +20 +300 +13 1 (to 280) 20 (to 300) 279 280 300 600 613 300 (to 600) 13 (to 613) 334

Subtraction by adding on. 846 - 458 = 388 846 - 458 +42 +300 +46 42 (to 500) 300 (to 800) 458 500 800 846 46 (to 846) 388

Subtraction by adding on. 2645 - 898 = 1746 2645 - 898 +2 +100 +1000 +645 2 (to 900) 100 (to 1000) 898 900 1000 2000 2645 1000 (to 2000) 645 (to 2645) 1746

Subtraction by adding on. 3567 - 742 = 2825 3567 - 742 +58 +200 +2000 +567 58 (to 800) 200 (to 1000) 742 800 1000 3000 3567 2000 (to 3000) 567 (to 3567) 2825

Subtraction by adding on. 3879 - 1352 = 2525 3879 - 1352 +48 +600 +1000 +879 48 (to 1400) 600 (to 2000) 1352 1400 2000 3000 3879 1000 (to 3000) 879 (to 3879) 2 5 1 2 1 5 1

Subtraction by adding on. 6457 - 2469 = 3988 6457 - 2469 +31 +500 +3000 +457 31 (to 2500) 500 (to 3000) 2469 2500 3000 6000 6457 3000 (to 6000) 457 (to 6457) 3 9 8 8

Subtraction by adding on. 5021 - 1989 = 3032 +1 +10 +1000 +1000 +1000 +20 +1 1989 1990 2000 3000 4000 5000 5020 5021 Th H T U 3000 30 2

Subtraction by adding on vertically 6008 - 2997 3 (3000) 3000 (6000) 8 (6008) 3011

Subtraction by adding on vertically 5003 - 1989 11 (2000) 3000 (5000) 3 (6008) 3014

5 2 3 9 - 1 5 6 7 3 (1570) 3 0 (1600) 4 0 0 (2000) 3 2 3 9 (5239) 3 6 5 3 1

4 1 1 1 5 2 3 9 - 1 5 6 7 3 6 7 2