A balance loses 8 units on each of 5 days. What is the total signed change in the balance across the 5 days?

Explanation

Losing 8 units on each of 5 days repeats the same downward move 5 times, which multiplies to 40 units lost, so the signed change lands 40 below zero. Answering 40 says how much was lost but records it as a gain, and combining the 8 with the 5 by addition mistakes a repeated change for a single one.