BGS - 01. Introduction to Numbers

Question 1

Negative Numbers (Temperatures)

If both numbers are negative, or both positive, remove the signs.
Subtract smaller number from larger number:

What is the temperature change:

-11℃ and -3℃

Answer 1

Remove signs, subtract smaller number from largest

11 - 3

8℃

Question 2

Negative Numbers (Temperatures)

If one number is negative, one is positive, remove the signs.
Add the two numbers together

What is the temperature change:

-3℃ and +7℃

Answer 2

Remove signs, add numbers together

3 + 7

10℃

Question 3

Negative number arithmetic

Adding a negative number is same as subtracting

7 + (-3) ⋉ 7 - 3

Answer 3

4

Question 4

Negative number arithmetic

Subtracting a negative number is the same as adding

(-5) - (-2) ⋉ (-5) + 2

Answer 4

(-3)

Question 5

Negative number arithmetic

Multiplying; when signs are the same the answer is positive.
If signs are different, answer is negative;

Positive x Positive = Positive
Negative x Negative = Positive
Positive x Negative = Negative

Answer 5

P x P = P
N x N = P
P x N = N

2 x 2 = 4
(-2) x (-2) = 4
2 x (-2) = (-4)

Question 6

Negative number arithmetic

Dividing; when signs are the same, the answer is positive
If signs are different, answer is negative

Positive ➗ Positive = Positive
Negative ➗ Negative = Positive
Positive ➗ Negative = Negative

Answer 6

P ➗ P = P
N ➗ N = P
P ➗ N = N

15 ➗ 3 = 5
(-15) ➗ (-3) = 5
(-15) ➗ 3 = (-5)