Bake me a cake as fast as you can. Roll it, pat it, mark it with a TEN. Today we're helping out at a bakery and people are buying so many baked goods! In this lesson, we learn to subtract by groups of ten. Using a place value chart, students subtract larger numbers by focusing on the tens place and taking groups of ten away. It looks like I bought too many croissants: 10, 20, 30... uh-oh.

Subtract multiples of 10 in the range 10-90 from multiples of 10 in the range 10-90 (positive or zero differences), using concrete models or drawings and strategies based on place value, properties of operations, and/or the relationship between addition and subtraction; relate the strategy to a written method and explain the reasoning used.