In week 8, the Lions hosted a Halloween afternoon contest against the Washington Redskins. Neither team scored in the 1st quarter. The Lions took an early lead in the second quarter with a 13-yard TD catch by Calvin Johnson. The Redskins tied it up with a 6-yard TD catch by Ryan Torain. Washington's Graham Gano kicked 2 field goals just before halftime, from 38 and 46 yards out. The only score of the 3rd quarter was a 2-yard TD catch by Brandon Pettigrew of the Lions. The Redskins took the lead in the 4th quarter with a 5-yard TD run by Keiland Williams; they went for a 2-point conversion and failed, however. The Lions took the lead back with a 7-yard catch by Calvin Johnson; they also failed to complete a 2-point conversion. The Redskins responded with a 96-yard kickoff return for a TD by Brandon Banks; they again failed to complete a 2-point conversion. The Lions retook the lead with a 10-yard TD catch by Calvin Johnson, and completed a 2-point conversion. The Lions added to their lead a few minutes later with a 32-yard field goal by Jason Hanson. The Lions sealed their win with a fumble recovery by Ndamukong Suh which he ran back 17 yards for a touchdown, but the 2-point conversion failed. With the win, not only did the Lions improve to 2-5, but it was the first time since 2007 that the team has won back-to-back home games. Curiously, this was the Lions' second consecutive blacked-out home game against the Redskins. The Lions had won the previous season's meeting as well.
Question: How many yards long were Calvin Johnson's touchdowns on average?
Answer: 10