She can use 68 + 20 = 88 to help by noticing that the 20 is ahead of 19 by 1. She can easily mentally turn the 20 into a 19 and realized that the 88 would become 87.
First, start off with the x-axis. -6.5, 1 becomes 6.5, 1. This is because point T is 6.5 to the left of the x-axis line, so our new point would be 6.5 to the right of the x-axis line. Same thing for the y-axis, (6.5, 1) would become (6.5, -1).
