2.NBT.5 – Fluently add and subtract within 100 using strategies based on place value, properties of operations, and/or the relationship between addition and subtraction.

**Internet Resources (Videos, Websites, etc.)**

K-5 Math Teaching Resources

- 2 Digit Addition Split
- Four in a Row with Near Doubles (Version 2)
- Four in a Row with Near Doubles (Version 3)
- Close to 100
- Keep on Doubling
- Number Wheel Spin

Khan Academy

Learn Zillion Instructional Videos

NCTM Illuminations

- Addend Pairs to 12
- Balancing Discoveries
- Comparing Sets
- Counting to Find Sums
- Do It With Dominoes
- Electronic Abacus
- Exploring Adding with Sets
- Finding Addition Patterns
- Finding Sums to Six
- Hopping Backward to Solve Problems
- How Many Under the Shell?
- Mathematics and Football: Unit Overview
- Seeing Doubles
- Some Special Sums
- Ten Frame
- Using the Number Line to Compare
- What’s Left?

- Addition – two digits: Add a two-digit and a one-digit number – without regrouping
- Addition – two digits: Add a two-digit and a one-digit number – with regrouping
- Addition – two digits: Add two two-digit numbers – without regrouping
- Addition – two digits: Add two two-digit numbers – with regrouping
- Addition – two digits: Addition input/output tables – up to two digits
- Addition – two digits: Ways to make a number using addition
- Addition – two digits: Balance addition equations – up to two digits
- Subtraction – two digits: Subtract a one-digit number from a two-digit number – without regrouping
- Subtraction – two digits: Subtract a one-digit number from a two-digit number – with regrouping
- Subtraction – two digits: Subtract two two-digit numbers – without regrouping
- Subtraction – two digits: Subtract two two-digit numbers – with regrouping
- Subtraction – two digits: Subtraction input/output tables – up to two digits
- Subtraction – two digits: Ways to make a number using subtraction
- Subtraction – two digits: Balance subtraction equations – up to two digits
- Mixed operations: Add and subtract numbers up to 100
- Mixed operations: Addition and subtraction – ways to make a number – up to 100
- Mixed operations: Addition and subtraction – balance equations – up to 100
- Mixed operations: Which sign (+ or -) makes the number sentence true?

Wow! This is a great site with many activities to help with planning our CCES lessons. Thank you so much for sharing. I was becoming frustrated since this is our first year.