It was -3 C this morning but the temperature has gone up 13° over the course of the day. What is the temperature now?

If the temperature was -3°C in the morning and has gone up 13°C over the course of the day, the temperature now is:

-3°C + 13°C = 10°C

To find the current temperature, we add the increase in temperature to the starting temperature.

Starting temperature: -3 degrees Celsius
Increase in temperature: 13 degrees Celsius

To find the current temperature, we add -3 + 13:

-3 + 13 = 10

Therefore, the current temperature is 10 degrees Celsius.