This Problem Set is a part of the Lesson 11, Unit 4, Grade 1. In this lesson, students represent the addition of ten more with concrete objects and number bonds. (For example, they represent 4 as 3 and 1 together; 40 as "3 tens" and "1 ten" together; and 40 as 30 and 10 together.) After creating number bonds for several examples, they notice that only the unit has changed (for example, 3 bananas + 1 banana = 4 bananas, just as 3 tens + 1 ten = 4 tens).