Potential answers were collected from the class and two were provided. 17 and 35
The first student explained she started at 26 on the hundreds grid, hopped up 10 to 36 then subtracted 1 to get 26 + 9 = 35.
This was the student's page showing her work. She started at 26 on the number grid and hopped back 9 places to 17. She commented that this was not the most efficient way to solve the problem, but it worked for her.
Two students used addition to solve the problem resulting in the correct answer.