Use the image to answer the question.
A number line with arrows on both ends ranges from negative 40 to 60 in increments of 10. Closed points are marked at negative 35 and 55. A curved arrow points from 55 to negative 35 and is labeled as negative 90.
Joyce uses the subtraction algorithm to subtract −35−55 and gets the answer −90. She connects this expression and answer to a number line model. Fill in the blanks to explain what is shown in the number line model.
(2 points)
Using a number line, Joyce starts at the point
. She then finds that she needs to move
in the negative direction to get to −35. Therefore, −35−55=
.
Using a number line, Joyce starts at the point 55. She then finds that she needs to move 90 units in the negative direction to get to −35. Therefore, −35−55= -90.
Use the image to answer the question.
An illustration shows a row of 12 solid circles with a negative sign in the middle of each circle. The last 3 circles are crossed out with diagonal lines.
Conrad subtracts −12−(−3) using the subtraction algorithm and finds that the answer is −9. He connects this expression and answer to a two-color counter model. Fill in the blanks to explain what is shown in the two-color counter model.
(2 points)
Conrad starts with 12 negative counters and then takes away
negative counters. He is left with
negative counters. Therefore, −12−(−3)=
.
Conrad starts with 12 negative counters and then takes away 3 negative counters. He is left with 9 negative counters. Therefore, −12−(−3)=-9.
Use the image to answer the question.
A number line with arrows on both the ends ranges from 0 to 15 in 1 unit increments. Closed points are marked at 8 and 15.
Jones uses the subtraction algorithm to subtract 8−15 and gets the answer −7. They want to connect this expression and answer to a number line model. How should they complete their number line model to show why the answer is −7?
(2 points)
Jones should draw an arrow starting at
that connects to
. The arrow will show that they need to move
in the negative direction to connect the two numbers. Therefore, the answer is −7.
Jones should draw an arrow starting at 8 that connects to 15. The arrow will show that they need to move 7 units in the negative direction to connect the two numbers. Therefore, the answer is −7.
Using a number line, Joyce starts at the point 55. She then finds that she needs to move 90 units in the negative direction to get to −35. Therefore, −35−55= -90.
Using a number line, Joyce starts at the point marked at 55. She then finds that she needs to move in the negative direction to get to -35. Therefore, -35 - 55 = -90.
To find the answer, Joyce starts at the point marked at 55 and moves in the negative direction towards -35, which is a distance of 90 units. So the expression -35 - 55 is equal to -90.