Can someone please help me understand how 2.7+(-12)= -9.3
If you have money in your money box then you have a positive amount of money.
If you owe money to your mother then you have a negative amount of money - because you have got less than nothing.
say you have $2.70 in your money box
Now you want to buy something so you borrow 12 dollars and spend the 12 dollars straight away that's negative 12 dollars
so you now have $2.70 + -$12 = -$9.70
In other words if you work and earn another $9.70 and then you give all your money to your mother, you will be back to having 0.
Or you could just look at +- as a pattern
1++2 = 3
1++1 = 2
1+ 0 = 1
1+-1 = 0 (by continuing the pattern)
1+-2 = -1
etc
+118653 
