Subtraction using Place Value
Learning to subtract 2 digit numbers that are multiples of 10s by place value method.
Mapped to CCSS Section# 1.NBT.C.6
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.