Mental Addition and Subtraction

Compatible numbers for addition and subtraction are numbers that do what?  Numbers that equal tens or hundreds are the most common examples. 

• Easily combine to equal benchmark numbers

• Combine to equal benchmark numbers but with more difficulty

• Do not really exist

What is the name of the strategy that can use for solving problems with multidigit numbers, an amazingly powerful way to subtract and is particularly successful with students with disabilities?

• Adding single-digit numbers

• Subtracting single-digit numbers

• Think-addition strategy

When we add two numbers and do the addition we use the symbol

• +

• -

• =

• x

Taking away a smaller number from the big number is called

• addition

• subtraction

9 + 8 =

37 + 5 =

10 - 8 =

46 + 3 =

Addition

9+1=

Addition

6+1=