Grace has built her staircase and is building the house in front of the first step.
I signal: "Grace, let's look where your stairs lead. Let's pretend to go up them. Up, up, up, up... uh, oh!"
Grace notices: "The house needs to go at the other end. [She moves her house to the other end, but it is shorter than the top stair.] The stairs are too high. I don't know what to do."