Khan Academy
Khan Academy: Subtracting Two Digit Numbers Without Regrouping (Example 2)
Sal subtracts two-digit numbers (without regrouping) by thinking about tens and ones. Includes a video, transcript, and question and answer section. [2:20]
CK-12 Foundation
Ck 12: Elem Math: Overview of Mixed Operations Numbers to 100
[Free Registration/Login may be required to access all resource tools.] The video uses an example with addition and subtraction to show how to solve a multi-step problem including a description of the actual two-digit addition and...
CK-12 Foundation
Ck 12: Elem Math: Overview of Subtraction Numbers to 100
[Free Registration/Login may be required to access all resource tools.] The video explains two 2-digit subtraction problems one with regrouping and the other without regrouping.
CK-12 Foundation
Ck 12: Elem Math: Overview of Addition Sums to 100
[Free Registration/Login may be required to access all resource tools.] The video explains two 2-digit addition problems one with regrouping and the other without regrouping.
Math Mammoth
Math Mammoth: A Mental Math Trick: Addition With Nine and Eight
Learn a simple trick to help you add 9 or 8 to a number quickly, and how this can work with larger numbers ending in 9 or 8 as well. [8:59]
Math Mammoth
Math Mammoth: Adding Three or Four Single Digit Numbers Mentally
In this lesson, students are shown strategies for adding several single-digit numbers in their heads. [7:12]
Math Mammoth
Math Mammoth: Add and Subtract Multiples of 100: Mental Math
Learn how to add and subtract multiples of a hundred when working with 3-digit numbers. [8:14]
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]
Math Mammoth
Math Mammoth: Mental Addition of Two Digit Numbers
This video explains some strategies that are helpful for adding two-digit numbers in your head. [8:00]
Imagine Learning Classroom
Learn Zillion: Adding and Subtracting Using Doubles Facts
In this lesson, you will learn to add and subtract by using doubles. [3:42]
Math Mammoth
Math Mammoth: Number Rainbow and Fact Families With 12
Teaches strategies for learning the addition and subtraction facts for 12 using a number rainbow. Students are then presented with a subtraction facts drill where they practice along to the video. [6:40]
Math Mammoth
Math Mammoth: Mental Addition: Add 2 Digit and 1 Digit Number (With Regrouping)
Teaches mental math strategies for adding a two-digit and a one-digit number. [7:41]
Khan Academy
Khan Academy: Strategies for Adding 2 Digit Numbers
Sal goes through multiple strategies for adding 2-digit numbers. [3:15]
Khan Academy
Khan Academy: Strategies for Adding 2 Digit Numbers
Watch as Sal goes through multiple strategies for adding 2-digit numbers. [3:15]