Add & Subtract up to 1000 with an Open Number Line - 2nd & 3rd Grade

An open number line is a very versatile tool for helping with addition and subtraction within 1000. The visual support allows students to develop their knowledge of place value and rounding in an informal way.

The worksheets
There are 11 levels of differentiation for both Addition and Subtraction. Starting with a 3-digit number  plus or minus 100 then progressing in steps until both numbers are randomly generated 3-digit numbers. 

At each level you have an (almost) unlimited number of printable worksheets that could be used throughout the year.

• - 1st number - 3 digits,  2nd number - 100

• - 1st number - 3 digits,  2nd number between 95 and 105

• - 1st number - 3 digits,  2nd number between 90 and 110

• - 1st number - 3 digits multiple of 10,  2nd number - 100 +/ -  a multiple of 10 between 10 & 50

• - 1st number - 3 digits,  2nd number - 100 +/ -  a multiple of 10 between 10 and 50

• - 1st number - 3 digits,  2nd number - multiple of 100

• - 1st number - 3 digits,  2nd number - multiple of 100 +/ - 5

• - 1st number - 3 digits,  2nd number -  multiple of 100 +/ - 10

• - 1st number - 3 digits multiple of 10,  2nd number - multiple of 100 +/ - a multiple of 10 between 10 & 50

• - 1st number - 3 digits multiple of 10,  2nd number - multiple of 100 +/ - a multiple of 10 between 10 & 50

• - 1st  & 2nd numbers both 3 digits
  

An example of the specific level being worked on is generated at the top of each worksheet at the click of a button. Besides being a memory jogger for students, it could be used to introduce the assignment when projected onto an Interactive whiteboard.

Why (almost) Unlimited Worksheets ?

At the click of a button all numbers are randomised, so you can create as many different worksheets for classwork, homework, review, preparing for assessments, or just simply practice at any time to keep the skill alive throughout the whole year.  They are straightforward enough to be left for a replacement teacher with minimal instructions. You will never run short of new worksheets for your students to practice with.

Are there Answers ?

Yes. Full graphical solutions are provided for all worksheets

Note

These resource works with the official  Adobe Acrobat Reader on Windows or Mac computers.

Common Core references

CCSS2.NBT.B.7

Add and subtract within 1000, 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. Understand that in adding or subtracting three-digit numbers, one adds or subtracts hundreds and hundreds, tens and tens, ones and ones; and sometimes it is necessary to compose or decompose tens or hundreds.

CCSS2.NBT.B.8

Mentally add 10 or 100 to a given number 100–900, and mentally subtract 10 or 100 from a given number 100–900.

CCSS2.NBT.B.9

Explain why addition and subtraction strategies work, using place value and the properties of operations.

CCSS3.NBT.A.2

Fluently add and subtract within 1000 using strategies and algorithms based on place value, properties of operations, and/or the relationship between addition and subtraction.