10% of 70 is 7
.1 times 70 is 7
so the answer should be 70
In the real world you are not going to have a calculator on you 24/7. Nor will you have a pencil or paper to do longhand. You need to know how to accurately estimate your answers in order to be successful.
Answer: Choice A) Add 3.8 to both sides of the equation
Explanation:
If we knew the value of w, then we would replace it and apply PEMDAS.
However, we don't know the value of w, so we undo each step of PEMDAS going backwards.
We start with the "S" of PEMDAS, and undo the subtraction. To undo subtraction, you apply addition. To undo that "minus 3.8" we add 3.8 to both sides.