Problem Solving When Adding and Subtracting Decimals

What is the rule for adding and subtracting positive decimals?

• Line up the decimals and then add/subtract normally

• You do not have to worry about placement of the decimal

• Forget the decimal and move it that many spaces at the end

• Drop it down and move it to the right once

When adding or subtracting decimals, you must line up your decimal points.

• TRUE

• FALSE

what is the first step when you add a decimal?

• solve the problem

• see what your dealing with

• line up the decimal

• add

What is the first step to solving adding and subtracting decimals?

• Place Value

• Carry and Borrow

• Aligning Decimal Points

• Rounding Off

When you subtract decimals, you do not need to line up the decimal points throughout the problem!

• TRUE

• FALSE

How do you solve problems that involve adding decimals?

• Find the magic number

• Bring UP the decimal point

• Line up the decimals

• Completely ignore the decimal

How do you solve problems that involve subtracting decimals?

• Find the magic number

• Bring UP the decimal point

• Line up the decimals

• Completely ignore the decimal

Did the student solve this problem correctly?

• Yes, this is correct

• No, it is incorrect. They forgot to use the magic number.

• No, it is incorrect. They forgot to bring the decimal down.

Did they solve this problem correctly?

• Yes, the problem is correct

• No, it is incorrect. They needed to find the magic number.

• No, it is incorrect. They lined up the digits wrong.

Did I set this equation up correctly?

• Yes

• No