Khan Academy
Khan Academy: Adding 2 Digit Numbers Without Regrouping 2
Demonstrates how to add 23 to 45 using drawings of base ten cubes to represent 1s and 10s. [2:34]
Khan Academy
Khan Academy: Adding With Regrouping
Demonstrates how to add 35 to 27 using drawings of base ten cubes to represent 1s and 10s. [4:36]
Khan Academy
Khan Academy: Strategies for Adding 2 Digit Numbers
Watch as Sal goes through multiple strategies for adding 2-digit numbers. [3:15]