Adding Real Numbers—Number Line MethodGUIDED EXAMPLE 1 Find the total value of the withdrawals for the day.

RESULTSTEP

The total value of the withdrawals isAnswer

Determine the total withdrawal.

Represent the withdrawal of $10on the number line.

Represent the withdrawal of $30 on a number line.

You write a check for $30 at dinner, and then later you write a check for $10 at the movies.

SOLUTION

Represent with chips.

Represent with chips.

Adding Real Numbers—The Chip MethodGUIDED EXAMPLE 2 Add.

STEP RESULT

SOLUTION

Represent the addition with chips.

Add the chips.

Answer

Adding Real Numbers with the Same SignGUIDED EXAMPLE 3 Add.

STEP RESULT

SOLUTION

Add the numerical parts.

Give the answer the sign of the numbers being added.

Answer

Both numbers are negative, so thesign of the sum is negative.

Adding Real Numbers with the Same SignGUIDED EXAMPLE 4 Add.

STEP RESULT

SOLUTION

Add the numerical parts.

Give the answer the sign of the numbers being added.

Answer

Both numbers are negative, so the sign of the sum is negative.

Adding Real Numbers with the Same SignGUIDED EXAMPLE 5 Add.

STEP RESULT

SOLUTION

Add the numerical parts.

Give the answer the sign of the numbers being added.

Answer

Both numbers are negative, so the sign of the sum is negative.

Adding Real Numbers with the Same Sign

STEP RESULT

SOLUTION

GUIDED EXAMPLE 6 Add

Add the numerical parts.

Give the answer the sign of the numbers being added.

Answer

All three numbers are negative, so the sign of the sum is negative.

Study GuideThe absolute value of a number is the distance between that number and zero on a number line.

To add two numbers of the same sign, add the absolute values, or numerical parts, of the numbers and give the answer the same sign as the numbers being added.

Procedure: ADDING TWO NUMBERS WITH THE SAME SIGN

Note: A number written without a sign is assumed to be positive.