Need help with 7th grade algebraic reasoning question?

Question

Using order of operations for algebraic reasoning. How the heck do I do this?

Use the numbers 3, 5, 6, 2, 54, and 5 in that order to write an

expression that has a value of 100

Answer 1

I do it with trial and error.

For the last number 5, I assume that the operation could either be a plus or minus, because divided or multiplying is impossible.

The second to the last 54 must be a plus. Minus could significantly reduce the total of the first 4 numbers.

If 5 is added to 54 , the total is 59. It means that the total of the first 4 numbers must be 41. This total is impossible to get from 3,5,6 and 2.

If 5 is subtracted from 54, you will get 49. The first 4 numbers then must be 51. This is achievable.  3 x 5 = 15,  6^2 = 36... 15 + 36 = 51.

So the equation is...

(3 x 5) + 6^2 + 54 - 5 = 100