A number line is shown below. The numbers 0 and 1 are marked on the line, as are two other rational numbers a and b.
Decide which of the following numbers are positive and which are negative.
a - 1
Choose p for positive and n for negative and put the appropriate letter
in the blue box next to each expression,
a - 2
b
0
1
-b
a
a + b
Choose one of the expressions and explain how you knew it was positive or
negative:
a - b
ab + 1