Review Test in Math 6_Addition and Subtraction of Integers

Adding two positive numbers is always positive.

Just like : 1 + 1 = 2

32 + 12 = 44

Adding two negative numbers will take a negative answer.

example:

-2 + (-3) = -5

Simply add the two numbers and copy the same sign.

Solve them one at a time :

-7 + 7 = 0

0 - 5 = - 5

-4 + 13 = 9

In adding a positive and negative integer, subtract the absolute values. The sum has the sign of the addends with greater absolute value.

l-4l = 4 while l13l = 13

using the absolute value 13 is greater, so take the sign of 13 which is positive.

Then subtract 13 to 4 the answer is 9. Therefore -4 +13 = 9.

Subtract +2 from -7

Remember: Keep, Change, Change, Add

-7 - (+2) = -7 + (-2) = -9

Remember: KCCA

42 - (-36) = 42 + 36 = 78

Take note: Keep, Change, Change and then Add

12 + ( - 35)

35 - 12 = 23

Using the absolute we have 35 has the greater value, so we take or copy the sign of it. Therefore the answer is - 23 / negative 23.

Solve first the integers having the same sign.

-4 + -2 = -6

Then continue adding to the remaining number.

-6 + 1 = -5