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 two-digit 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 two-digit 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 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, 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 two-digit 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