Common Core: Number & Operations in Base Ten

2.NBT.B7

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 … Read More “2.NBT.B7”

October 1, 2018
2.NBT.B8

Mentally add 10 or 100 to a given number 100-900, and mentally subtract 10 or 100 from a given number 100-900.

October 1, 2018
2.NBT.B9

Explain why addition and subtraction strategies work, using place value and the properties of operations.1

October 1, 2018
2.NBT.A1

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:

October 1, 2018
2.NBT.A1a

100 can be thought of as a bundle of ten tens — called a “hundred.”

October 1, 2018
1.NBT.B3

Compare two two-digit numbers based on meanings of the tens and ones digits, recording the results of comparisons with the symbols >, =, and

October 1, 2018
1.NBT.C4

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. … Read More “1.NBT.C4”

October 1, 2018
1.NBT.C5

Given a two-digit number, mentally find 10 more or 10 less than the number, without having to count; explain the reasoning used.

October 1, 2018
1.NBT.C6

Subtract multiples of 10 in the range 10-90 from multiples of 10 in the range 10-90 (positive or zero differences), 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.

October 1, 2018
1.NBT.A1

Count to 120, starting at any number less than 120. In this range, read and write numerals and represent a number of objects with a written numeral.

October 1, 2018
1.NBT.B2

Understand that the two digits of a two-digit number represent amounts of tens and ones. Understand the following as special cases:

October 1, 2018
1.NBT.B2a

10 can be thought of as a bundle of ten ones — called a “ten.”

October 1, 2018