Community property
a d simplify

Ah, the commutative property.

a + b = b + a

xy = yx

When using the commutative property - a good way to remember it is to think of a community, in which each community member helps one another to a mutual outcome.

Using the commutative property we can rearrange this equation into a more sensical format:

-8.9 + 6.7 - 1.1

6.7 - 1.1 - 8.9

6.7 - 1.1 = 5.6

5.6 - 8.9 = -3.3