Adding 1-digit numbers
3+5
What is 8
12+12
What is 24
100+100
What is 200
1111+2222
What is 3,333
324+12+222
What is 558
3+4
24+12
What is 36
301+123
What is 424
1234+1234
What is 2,468
123+123+123
What is 369
3+8
What is 11
34+45
What is 79
345+234
What is 579
1234+5678
What is 6,912
123+234+345
What is 702
7+5
What is 12
45+78
765+948
2468+1357
What is 3,825
386+897+4567
What is 5,850
9+9
What is 18
99+99
What is 198
898+989
What is 1,877
9898+8989
9,999+9,898+8888
What is 19,897