Adding 3-digit Numbers

• Add 3-digit numbers using an open number line? (2nd grade)
• Add 3-digit numbers using expanded form? (2nd grade)

Subtraction 

• Base Ten Sketch
• Keep One Break One
• Expanded Form (without Regrouping)
• Compensation for Subtraction  (This is Great When You have A LOT of Zeroes)
• Subtraction Using a Number Line (Regrouping)
• Expanded Form (with Regrouping)

 

 

 

 

 

Addition Tutorials

How do I add 3-digit numbers using an open number line?

How do I add 3-digit numbers using expanded form?

How do I solve for a missing addend by counting up?

Subtraction Tutorials

How do I subtract with regrouping using a base-ten sketch?