A football team gained 12 yards on one play, lost 40yards on another, and gained 34 yards on the last play of the first half. They had already gained 345 yards during the half. What was the total yardage gain for the first half?

To determine the total yardage gain for the first half, we need to add up the yardage gained on each play.

1. The team gained 12 yards on one play.
2. They lost 40 yards on another play.
3. They gained 34 yards on the last play of the first half.

To find the total yardage gain, we can add up these yardages:

12 yards + (-40) yards + 34 yards

When adding or subtracting integers, we sum or subtract the numbers together, regardless of their signs:

12 + (-40) + 34

Now, let's simplify the calculation:

12 + (-40) + 34 = -26 + 34

To add these numbers, we can treat the positive and negative sign as directions:

-26 + 34 = 34 - 26

We subtract 26 from 34:

34 - 26 = 8

Therefore, the total yardage gain for the first half is 8 yards.

345 + 12 + 34 - 40 = ?