Common Core · Mathematics
2.NBT.9
Grade 2 · Number & Operations in Base Ten
Explain why addition and subtraction strategies work, using place value and the properties of operations.
- Official code
- CCSS.MATH.CONTENT.2.NBT.9
- Short code
- 2.NBT.9
- Subject
- Mathematics
- Grade
- Grade 2
- Domain
- Number & Operations in Base Ten
More Grade 2 Number & Operations in Base Ten standards
2.NBT
Number and Operations in Base Ten
2.NBT.1
Understand that the three digits of a three-digit number represent amounts of...
2.NBT.1a
100 can be thought of as a bundle of ten tens — called a "hundred."
2.NBT.1b
The numbers 100, 200, 300, 400, 500, 600, 700, 800, 900 refer to one, two, three,...
2.NBT.2
Count within 1000; skip-count by 5s, 10s, and 100s.
2.NBT.3
Read and write numbers to 1000 using base-ten numerals, number names, and expanded form.
2.NBT.4
Compare two three-digit numbers based on meanings of the hundreds, tens, and ones...
2.NBT.5
Fluently add and subtract within 100 using strategies based on place value, properties...
2.NBT.6
Add up to four two-digit numbers using strategies based on placevalue and properties...
2.NBT.7
Add and subtract within 1000, using concrete models or drawings and strategies based...
2.NBT.8
Mentally add 10 or 100 to a given number 100—900, and mentally subtract 10 or 100 from...
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