154579

What I did is, I looked at the problem closely and I saw that it said you need two steps up and two steps down, it also said you need 4 blocks to make it a full staircase. It was like multiplying it by itself for example 2 x 2 =4 . So what we needed was five steps up and down, so I multiplied 5 x 5 which = 25, so I need 25 blocks to build the steps