## Did Mariah Make a Mistake?

Mariah explained how to add -8 + (-4) by using the number line below. Mariah stated that -8 + (-4) = -4 by counting four spaces to the right from -8 on the number line and ending at -4. Which

## Miss Reyes’ Students

Miss Reyes put -7 + 5 = ? on the board and asked her students to represent the problem with a number line.  Charlie drew the number line below. Which of the following correctly describes Charlie’s number line? A.  The

## Maya is Selling Bottled Water

Maya bought 72 bottles of water to sell at the concession stand for the weekend. By Sunday morning, she sold 63 bottles of water. A. Represent the situation as the addition of integers, and solve the problem to determine how

## Alexis is Subtracting on a Number Line

Alexis wants to represent the subtraction problem below on a number line. 45 – 8 If she does not decompose the numbers, describe two ways Alexis can represent this problem on a number line, and compare this to the number

## Find Alec’s Mistake

Alec used a number line to solve (-8) – (-7). A. Explain the mistake on Alec’s number line. B. Draw a number line that correctly shows (-8) – (-7), and write the solution.

## Find Yanni’s Mistake

Yanni used a number line to solve (-13) + (-9). A. Explain the mistake on Yanni’s number line. B. Draw a number line that correctly shows (-13) + (-9), and write the solution.

## Tierra is Adding on a Number Line

Tierra wants to represent the addition problem below on a number line. 12 + 20 She wants to draw an arrow starting from 12. Her friend says that the arrow should start from 20. Use two number lines to determine

## Trista’s Negative Numbers

Trista says that the difference between two negative numbers is always a positive number. She provides the reasoning below. Since -4 – (-9) = + 5 and -2 – (-3) = + 1, it can be said that the difference between

## Writing a Rule for Adding Numbers with Unlike Signs

Samuel is writing a rule for adding numbers with unlike signs. He writes that when adding two numbers with unlike signs, the sum is always positive. He writes that he knows this is true because he has tried many examples.

## Using a Number Line for the Sum of Two Negatives

Samantha thinks that the sum of two negative numbers is always negative. Her teacher asked her to use a number line to explain her reasoning. Draw a number line Samantha could use to explain her thinking.