Which is another way to check the sum of 52 + 23 + 10 + 78? A. 78 + 10 + 23 + 52 B. 78 – 52 – 10 – 23 C. 163 – 52 + 23 + 10 + 78 D. 78 – 52 + 10 + 23

First, you would do the math. 
52 + 23 + 10 + 78 = 163

Now, using the process of elimination and common sense, we can narrow down the answer to A. All you have to do is check it. 
78 + 10 + 23 + 52 = 163

So, 78 + 10 + 23 + 52 = 52 + 23 + 10 + 78

Your answer would be A. 78 + 10 + 23 + 52