Adding and Subtracting Integers and Decimals

When adding decimals with the same sign you.....

• subtract and take the sign of the larger number
• add the opposite
• add and keep the sign
• subtract and keep the sign

When adding decimals with different signs you....

• subtract and take the sign of the larger number
• add the opposite
• add and keep the sign
• subtract and keep the sign

Rewrite the problem as addition.

-5.66 - (-4.1)

• 5.66 + (-4.1)

• -5.66 + 4.1

• -5.66 + (-4.1)

• -5.66 - 4.1

-23.4 - 3.4= 

• -20
• 26.8
• -26.8
• 20

-40 + 15.05= 

• 55.05
• 24.95
• -24.95
• 14.65

When adding rational numbers with the same sign, you must:

• Subtract and keep the sign of the biggest number

• Add together and keep the sign

• Keep, change, switch

• Add the opposite

16 - (-9) 

• -7
• 11
• 15
• 25

-2 - (-10) 

• -12
• 12
• 8
• -8

-9 + 9

• 18
• -18
• 0
• 81

-7.79 + 5.4

• 4.61
• -2.19
• -2.39
• 2.11