Big Idea:Students have spent time building the numbers 11-19. This lesson gives them the opportunity to go at it from the other direction, taking the numbers and breaking them apart into a ten and some extra.
Big Idea:Students sweat in this rigorous lesson about grouping into tens! Students apply what they know about tens to early division problems, focusing on MP1, "Make sense of problems and persevere in solving them".
Big Idea:Students help Little Bear get ready for his party in this lesson where they decompose large numbers into groups of ten. These problems help students apply the key aspects of 1.NBT.B.2a to real life problems!