First Grade Number and Operations in Base Ten 

Basic place value, addition and subtraction. Just click on the blue links to display or print pdfs. 

Standards 
Practice
Pages


Extend the counting sequence  Cluster 1 

Standard 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.  Count Shapes Answers 1.NBT.1.a 
Count to 120 Twice Answers 1.NBT.1.b 
Understand place value  Cluster 2 

Standard 1.NBT.2:
Understand that the two digits of a twodigit number represent amounts
of tens and ones. Understand the following as special cases: 
Bundle Ones to Tens Answers 1.NBT.2.a 
Identify Number of Tens Answers 1.NBT.2.b 
Standard 1.NBT.3: Compare two twodigit numbers based on meanings of the tens and ones digits, recording the results of comparisons with the symbols >, =, and <.  Break and Compare Answers 1.NBT.3.a 
Compare 2 Digits B Answers 1.NBT.3.b 
Use place value understanding and properties to add and subtract  Cluster 3  
Standard 1.NBT.4: Add within 100, including adding a twodigit number and a onedigit number, and adding a twodigit 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 twodigit numbers, oneadds tens and tens, ones and ones; and sometimes it is necessary to compose a ten.  Add Objects Answers 1.NBT.4.a 
Carry a Ten Answers 1.NBT.4.b 
Standard 1.NBT.5: Given a twodigit number, mentally ﬁnd 10 more or 10 less than the number, without having to count; explain the reasoning used.  Add Ten Explain Answers 1.NBT.5.a 
Subtract 10 Explain Answers 1.NBT.5.b 
Standard 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.  Subtract Sets of 10 Answers 1.NBT.6.a 
Subtract 10s and Explain Answers 1.NBT.6.b 