The difference expression is an illustration of compatible numbers
The next step is to add 9 to both sides of the equation
How to determine the next step
The procedure is given as:
888 - 300 = 588
The actual expression is given as:
888 - 291
The difference between -291 and -300 is -9
This means that, Gillian subtracted 9 to -291 to get compatible numbers
The next step would be to add 9 to both sides of the equation
Read more about compatible numbers at:
https://brainly.com/question/7068223
