# Number and Operations in Base Ten (NBT)

• 1.NBT.A  Extend the counting sequence.
• 1.NBT.A.1  Count to 120 by 1's, 2's, and 10's starting at any number less than 100. In this range, read and write numerals and represent a number of objects with a written numeral.
• 1.NBT.B  Understand place value.
• 1.NBT.B.2  Understand that the two digits of a two-digit number represent groups of tens and ones. Understand the following as special cases:
1. 10 can be thought of as a group of ten ones — called a "ten".
2. The numbers from 11 to 19 are composed of a ten and one, two, three, four, five, six, seven, eight, or nine ones.
3. The numbers 10, 20, 30, 40, 50, 60, 70, 80, 90 refer to one, two, three, four, five, six, seven, eight, or nine tens (and 0 ones).
• 1.NBT.B.3  Compare two two-digit numbers based on meanings of the tens and ones digits, recording the results of comparisons with the symbols >, =, and <.
• 1.NBT.C  Use place value understanding and properties of operations to add and subtract.
• 1.NBT.C.4  Demonstrate understanding of addition within 100, connecting objects or drawings to strategies based on place value (including multiples of 10), properties of operations, and/or the relationship between addition and subtraction. Relate the strategy to a written form. See Table 1.
• 1.NBT.C.5  Given a two-digit number, mentally find 10 more or 10 less than the number, without having to count.
• 1.NBT.C.6  Subtract multiples of 10 in the range of 10 to 90 (positive or zero differences), using objects 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 form.

*Please note that students at CTA Independence are accelerated in math therefore are learning the level one year above their current grade.