Problem: (1+ 2 + 3 + 4 + 5 + 6 + 5 + 4 + 3 + 2 + 1) ÷ 6 = ______
Method: This sequence from 1 to 6 and then back to 1 is called a tower. From 1, the sequence goes up to 6 and then back to 1. It is like you climbing a mountain. When you get to the top of the mountain, you then go down the other side.
To compute the sum of the tower, you multiply the number at the top of the tower times itself. It this case, the sum is 6 x 6 = 36. Finally, we need to divide by 6 to get the final answer to the problem.