Question

On a cold February morning, Colton checked the temperature on his phone and saw that it was -3ºC. When he checked again after school, the temperature had dropped 3°C. What was the temperature after school? To solve the problem, Ellen subtracted -3 - (-3) and came up with an answer of 0°C. Is Ellen correct? Why or why not?​

Answer 1

Ellen is incorrect, -3 subtracted by 3 gets you -6. Ellen is wrong because she subtracted -3 instead of just 3. Subtracting a negative number is the same thing as adding.