Question

at 6 a.m. the temperature was -8 Celsius and noon the temperature was 3 Celsius what was the change of temperature between 6 a.m. and noon

Answer 1

To do this subtract -8 by 3 (3 - -8). To do this, change -8 into positive 8 and the subtraction sign to an addition sign.  It would basically be 3 + 8.  There was an 11 degrees change between 6 am and noon.