Add within 100, including adding a two-digit number and a one-digit number, and adding a two-digit number and a multiple of 10, 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. Understand that in adding two-digit numbers, one adds tens and tens, ones and ones; and sometimes it is necessary to compose a ten.

Lesson Planning and Activity Resources

These tasks are from PIMSER and were written for 1st - high school. Use knowledge of your classroom to determine entry and exit points for your lessons.

Grade 1 Unit: Understanding Place Value
(from Georgia Department of Education)
This unit addresses KCAS 1.NBT.2-6 and 1.MD.4.
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1.NBT--Interactive games for Numbers & Operations in Base Ten

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Interactive Materials that use addition or subtraction to solve the problem.
Worksheets that have finding the sum of numbers within 100.
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Number Bond Machine
Teacher can set the total. One number is generated randomly, and then
students must calculate the missing number. Great for mental math, counting
on, subtraction, etc.