Answer:
1.623
Explanation:
Subtract 55.78 from 57.403
57.403 - 55.78 = 1.623
To find the difference between two numbers, you just have to subtract. I'm not sure if it applies in this exact problem. But it's the only way I know how to do it. If 1.623 doesn't work, try 16.23. I hope this helps.