Apply addition, subtraction, multiplication and division rules
Key notes
On a number line,
- Numbers to the left of 0 are negative.
- Numbers to the right of 0 are positive.
Learn with an example
The number line shows an unknown number, b.
Is 3b positive or negative?
Determine if b is positive or negative.
The unknown number b is to the left of 0. So, b is negative.
Determine if 3b is positive or negative.
In the expression 3b, 3 is positive and b is negative. The product of a positive number and a negative number is negative. So, 3b is negative.
The number line shows an unknown number, v.
Is 5v positive or negative?
Determine if v is positive or negative.
The unknown number v is to the right of 0. So, v is positive.
Determine if 5v is positive or negative.
In the expression 5v, 5 is positive and v is positive. The product of two positive numbers is positive. So, 5v is positive.
The number line shows an unknown number, u.
Is 3u positive or negative?
- positive
- negative
Determine if u is positive or negative.
The unknown number u is to the left of 0. So, u is negative.
Determine if 3u is positive or negative.
In the expression 3u, 3 is positive and u is negative. The product of a positive number and a negative number is negative. So, 3u is negative.
Let’s practice!🖊️
