AMC 8 Daily Practice - Calculation Tricks by Grouping

By observing the arithmetic expression, we notice that the sum of the first four numbers is 0:

Examining the next set of four numbers, we find their sum is also 0:

Thus, the original expression can be rewritten as:

The problem now reduces to determining how many such groups exist. From 169 to 9, there are a total of 161 numbers.

When divided into groups of four, we get: groups with a remainder of 1.

Therefore, the original expression can be represented as:

The final result is .