2. Subtract 10 or 100
Practice subtracting 10 or 100 mentally from a 3 digit number. Subtracting 10 or 100 from a number is the same as decreasing the amount of tens or hundreds in a number. This should be simple for students comfortable in place value concepts and they should not require the use of models or pictures for help. Building mental fluency in such special cases of subtraction helps to contribute towards overall proficiency in subtraction.
Common Core Alignment
2.NBT.8Mentally add 10 or 100 to a given number 100—900, and mentally subtract 10 or 100 from a given number 100—900.