Skyscraper is a compound sign. First, sign building, stacking one flat hand on top of the other, and vice versa, as you progressively move your hands upward.
Then form your dominant hand into a fist with the index finger sticking up. Move your pointer finger upward until it is past your head, emphasizing that a skyscraper is a very tall building.
Teach your toddler the skyscraper sign when you are in the city, and you want to describe the very tall buildings off in the horizon.
This is a useful flash card taught best in conjunction with flash cards pertaining to other types of buildings and structures that you will find in a busy city.