Teaching number bonds (compliments, fact families) using unifix cubes is a fun, hands on way to get kids involved! Sit the students in a circle, give each student 10 unifix cubes (if you're working on compliments of 10). The students hide their rod of ten unifix cubes behind their back and break them into two parts without looking. Then, ask the class to show their bonds at the same time. For this activity I asked a few volunteers to come to the middle of the rug and build their number bonds, using paper plates, straws and standard form number cards.