1. Math in the Workplace
Negative numbers

2. Adding Signed Numbers
If the signs are the same, add the numbers and keep the sign.
(-4)+(-10)= =14
If the signs are opposite, subtract the numbers and keep the sign of the number with the highest value.
(-4)+10=6 4+(-10)= -6

3. Subtracting Signed Numbers
First, change the problem from subtraction to addition. Then change the sign of the 2nd number. (or Add the opposite)
(-4) – (-10)= (-4) +(+10)=
(-4) – (+10)= (-4) + (-10)=
Then, add the signed numbers as usual.
(-4) +(+10)= 6
(-4) + (-10)= -16

4. Adding/Subtracting on the number line
3+5=8
-4+5=1
-9+5=-4
9-7=2 or 9 + (-7) = 2
3-7=-4 or 3 + (-7) = -4
-1-7=-8 or -1 + (-7) = -8

5. Multiplying and Dividing Signed Numbers
When multiplying and dividing, the rules are the same:
If the signs are the same, the answer is positive.
(-4) x (-2) = x 2 = 8
(-4)/(-2) = 2 4/2 = 2
If the signs are opposite, the answer is negative.
(-4) x (2) = -8 (4) x (-2) = -8
(-4) / 2 = / (-2) = -2

6. Multiplying on a number line
(-2) x 4= (-8)
(-4)x2= -8
4 x 2= 8
2 x 4 = 8
(-2)+(-2)+(-2)+(-2)= (-8)
(-4) + (-4) = (-8)
4 + 4 = 8
= 8
If the multiplier is negative, go the opposite way
(-2) x (-4)= 8
2 x (-4)= (-8)

7. Dividing on a Number Line
video