1. Adding

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

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

4. Formal
Written
Method
Partitioning
Vertically + +
1 0 4 1 3 1 6 1
1 2 0
1 6

5. Subtracting

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

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

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

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

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

11. Subtraction by adding on.
= 2525
+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

12. Subtraction by adding on.
= 3988
+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

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

14. Subtraction by adding on vertically 3
(3000)
3000
(6000) 8
(6008)
3011

15. Subtraction by adding on vertically 11
(2000)
3000
(5000) 3
(6008)
3014

16. 3
(1570)
3 0
(1600)
(2000)
(5239) 3 6 5 3 1

17. 4 1 1 1 3 6 7 2