**NUMBER AND OPERATIONS IN BASE TEN**

**Extend the counting sequence**

**1.NBT.A.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.

**Sample Activities:**

Missing Number Grids 1-50

**Also included in 1st Grade Math Centers:**

**Counting Cards (Set 3)**

**Ten Frame Path**

**Base Ten Path**

**Number Path**

**Understand place value**

**1.NBT.B.2** Understand that the two digits of a two-digit number represent amounts of tens and ones. Understand the following as special cases:

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

b. The numbers from 11 to 19 are composed of a ten and one, two, three, four, five, six, seven, eight, or nine ones.

c. 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).

**Sample Activities:**

Tens and Ones with Snap Cubes

**Build a Train **

**Also included in 1st Grade Math Centers:**

**Tens and Ones Game**

**Representing Two Digit Numbers**

**Base Ten Concentration (2 Digit)**

My Double Ten-Frame Riddle

**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 <.

**Sample Activities:**

Comparing Two Digit Numbers

Scoop It

**Also included in 1st Grade Math Centers:**

Ten Frame Compare

Greater Than 50

Who Has the Greater Sum? (v. 1)

**Who Has the Greater Sum? (v. 2)**

**Use place value understanding and properties**

of operations to add and subtract

**1.NBT.C.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.

**Sample Activities:**

**Sums of 90 **

**Subtract 10 on the Number Line**

**Lucky Six**

**Adding a Multiple of 10 (ver.1)**

**Also included in 1st Grade Math Centers:**

**Adding a 2-Digit and One Digit Number**

**Add Ten**

Adding Tens to a 2-Digit Number

Add Ten on the Number Line

What Number is ...?

**Addition Split (2 digit + multiple of 10)**

**1.NBT.C.5** Given a two-digit number, mentally find 10 more or 10 less than the number, without having to count; explain the reasoning used.

**Sample Activities:**

Ten More

Race Around -10 (v.1)

**Also included in 1st Grade Math Centers:**

***Race Around + 10 (v. 1)**

**1.NBT.C.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.

**Sample Activities:**

Subtract Ten

Subtract Multiples of Ten