1
Speed Grid (+): Fill in each cell by applying the operation to the row and column headers. Row headers: [4, 1, 2, 1], Column headers: [7, 7, 6, 4] =
2
Speed Grid (-): Fill in each cell by applying the operation to the row and column headers. Row headers: [6, 3, 9, 9], Column headers: [8, 6, 8, 4] =