Mathematics | Grade : 2
Domain - Number and Operations in Base Ten
Cluster - Use place value understanding and properties of operations to add and subtract.
[2.NBT.B.8] - Mentally add 10 or 100 to a given number 100–900, and mentally subtract 10 or 100 from a given number 100–900.
[2.NBT.A.1] -
Understand that the three digits of a three-digit number represent amounts of hundreds, tens, and ones; e.g., 706 equals 7 hundreds, 0 tens, and 6 ones. Understand the following as special cases:
[2.NBT.B.7] -
Add and subtract within 1,000, 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. Understand that in adding or subtracting three-digit numbers, one adds or subtracts hundreds and hundreds, tens and tens, ones and ones; and sometimes it is necessary to compose or decompose tens or hundreds.
[2.NBT.B.9] -
Explain why addition and subtraction strategies work, using place value and the properties of operations. [Note: Explanations may be supported by drawings or objects.]