Corban S. answered • 11/21/14

Passionate, Relatable and Creative Tutor for Math and Science

For part A remember that subtraction can always be rewritten as addition of the negative. Therefore:

- 1.2 - 0.5

is equvalent to

-1.2 + (-0.5)

which equals

**-1.7.**Joanna, however,

**adds**0.5 to -1.2 which equals -0.7, which is an incorrect answer for -1.2 - 0.5For part B what you have written (repeated below) is the correct answer.

*"- 0.5 reduced by - 0.2 That tells you that the equation is to start with the -0.5, so that would make Joshua's own answer correct, for now. It tells you to reduce by a negative number - "reduce" and "negative" together means "minus a minus" which is the same as "plus a plus" so when Joshua changes "- -0.2" to " + 0.2," his own answer is still correct. Joshua's own answer is correct, but he's not correct if he says both answers are the same. Micheal sets up the wrong equation, his solution to that equation is correct, but it's not the equation he was supposed to do."*