What does it mean to compose and decompose numbers? If you compose a number you out it together. If you decompose a number you break it apart. Our math standards state we can compose and decompose numbers 11-19. Students must see one of these numbers as 10 and some more. For example, the number 14 is 10 and 4 more. We would write that number sentence as 10+4=14.
This week we are using teen numbers and breaking the into 2 tens frames, place value, a number sentence, and words.