Number And Operations In Base Ten

Outcomes

Extend The Counting Sequence.
- 1.NBT.1
  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.
  
  Play Activities 71
  
  Examples
Understand Place Value.
- 1.NBT.2
  Understand that the two digits of a two-digit number represent amounts of tens and ones. Understand the following as special cases:
  
  Play Activities 39
  
  Examples
- 1.NBT.2.b
  The numbers from 11 to 19 are composed of a ten and one, two, three, four, five, six, seven, eight, or nine ones.
  
  Play Activities 18
  
  Examples
- 1.NBT.3
  Compare two two-digit numbers based on meanings of the tens and ones digits, recording the results of comparisons with the symbols >, =, and <.
  
  Play Activities 9
  
  Examples
Use Place Value Understanding And Properties Of Operations To Add And Subtract.
- 1.NBT.4
  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.
  
  Play Activities 60
  
  Examples
- 1.NBT.5
  Given a two-digit number, mentally find 10 more or 10 less than the number, without having to count; explain the reasoning used.
  
  Play Activities 19
  
  Examples
- 1.NBT.6
  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.
  
  Play Activities 9
  
  Examples