1.NBT.4:
Number And Operations In Base Ten
Use Place Value Understanding And Properties Of Operations To Add And Subtract.
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.
2.NBT.1:
Number And Operations In Base Ten
Understand Place Value.
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.5:
Number And Operations In Base Ten
Use Place Value Understanding And Properties Of Operations To Add And Subtract.
Fluently add and subtract within 100 using strategies based on place value, properties of operations, and/or the relationship between addition and subtraction.
2.NBT.7:
Number And Operations In Base Ten
Use Place Value Understanding And Properties Of Operations To Add And Subtract.
Add and subtract within 1000, 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.9:
Number And Operations In Base Ten
Use Place Value Understanding And Properties Of Operations To Add And Subtract.
Explain why addition and subtraction strategies work, using place value and the properties of operations.3
3.NBT.2:
Number And Operations In Base Ten
Use Place Value Understanding And Properties Of Operations To Perform Multi-Digit Arithmetic
Fluently add and subtract within 1000 using strategies and algorithms based on place value, properties of operations, and-or the relationship between addition and subtraction.
2.NBT.1a:
Number And Operations In Base Ten
Understand Place Value.
100 can be thought of as a bundle of ten tens - called a "hundred."