These are positive whole numbers from zero to infinity, ex: 0,1,2,3, …
Natural line
A number line is a line drawn to represent numbers, ex;
-4 -3 -2 -1 0 1 2 3 4 5 6
Ex: plot 1 and 5 on the same number line
Solution:
-4 -3 -2 -1 0 1 2 3 4 5 6
Comparing numbers using the following mathematical symbols
Symbol meaning
> greater than
< smaller than
≥ greater than or equal to
≤ smaller than or equal to
Ex: Place the < and > symbols between the following numbers
a)12>3 b) 0<1 c)5<7
Addition and subtraction of numbers using number line
Ex: evaluate the following on number lines
a)4+3 b)8-6
Solution: a) 4+3=7
-1 0 1 2 3 4 5 6 7 8 9
b) 8-6=2
-1 0 1 2 3 4 5 6 7 8 9
Multiplication and division of numbers
Multiplication
If a and b are natural numbers, then a*b or ab = (b + b + b + …b) a times
Example 3*4= 4+4+4 or 3+3+3+3= 12
Division
Example: Evaluate a)239/6 b)1302/31
Solution:
a) 59 239/4=59R3 42 1302/31=42
4 239 31 1302
20 124
39 62
3 62
Use of brackets
Whenever a bracket appears in an expression, we first solve in the bracket before any other.
Example: evaluate a) (3+2)6, b) 3+(2*6), c) [12+(8*9) +1] +5, d) (8+22) -(6+1)
Solution: According to BODMAS which means Bracket, Of, Division, Multiplication, Addition, Subtraction;
a)30 b)15 c)90 d)5
