Is the sum of -67 + 41 positive or negative?
Negative
Use a model to find -10+12. Show your work.
-10+12=2
Possible models: number line, integer chips
Jeremy says that the sum of two numbers can never be negative. Explain why Jeremy's reasoning is incorrect. Use a model. Show your work.
Possible explanation: 4+(-6)=-2. The sum of these two numbers is negative.
Possible models: number line, integer chips
In the middle of a game, Dawn has a score of -17. At the end of the game, Dawn's score increases by 21. What is Dawn's score at the end of the game? Show your work.
Dawn's score is 4.
Possible student work: Number line
What situation could the expression (-19) - 4 represent?
Possible answer: The temperature was -19 degrees. Then it decreased 4 degrees.
Is the sum of 615 + (-615) + (8.4) positive or negative?
Positive
Use a model to find -9+9. Show your work.
Does the order in which you add -9 and 9 matter? Explain your reasoning.
-9+9=0
Possible models: number line, integer chips
No; Possible explanation: (-9)+9=0 and 9+(-9)=0
How is adding 2 + (-2) similar to adding 2 + 2? How is it different? Use words and models to explain. Show your work.
Possible explanation: They are similar because you start at 0 and move 2 units to the right. They are different because -2 is 2 units to the left and 2 is 2 units to the right. 2 + (-2) = 0 and 2 + 2 = 4.
68 points
Write a word problem to represent the following equation: -2 + (-3) = -5
Possible answer: A tadpole was 2 cm below the water's surface. It sank an additional 3 cm. What is the tadpole's new elevation?
Is the sum of 2.4 + (-2 6/10) positive or negative?
Negative
What is the sum of -26 and -37?
-63
What value of x makes the following statement true? 1.9 - x = a negative number
Any value greater than 1.9
15.3 ft apart
Is the sum of 9 4/5 + (-2 3/5) positive or negative?
Positive
Find 2 1/10 + (-5 2/5). Show your work.
-3 3/10
Why does -3.6 - (-4) have the same result as -3.6 + 4? Explain your reasoning.
An anchor is 15 3/5 m below the surface of the ocean. The anchor is lowered 4 1/5 m. Then it is pulled up 12 3/5 m. What is the anchor's new position relative to the surface of the ocean? Show your work.
-7 1/5; The anchor is 7 1/5 m below the surface of the ocean.
The sum of -21.8 and a number is positive. Identify a possible value for that number. Explain your selection.
Possible answer: 22; Since 22 is greater than 21.8, the sum of -21.8 and 22 is positive.