This math topic focuses on building number sense through problems that ask students to determine how many more of a certain item (represented visually) are needed to make a total of twenty. The questions involve various shapes and colors such as red circles, blue triangles, and orange squares. Each problem provides a visual representation of the items and offers multiple-choice answers. This type of exercise helps to reinforce basic addition skills, the concept of "making ten," and working with numbers less than 20.