Summary of chapter 2 (Real Numbers)
by Paul Phua

1. Addition and subtraction of intergers.
1.1. E.g. -8+7=-1
1.2. E.g. 80-23=-57
2. Any numbers that exist on the number line.
2.1. Negative and Positive numbers
2.1.1. E.g. -67, 789,1/4, 0.57,