Khan Academy
Khan Academy: Arithmetic and Pre Algebra: Addition 2
This video covers addition by counting and using a number line, followed by place value concepts and addition of two-digit numbers. Practice problems are available. [12:26]
Khan Academy
Khan Academy: Subtracting 1s, 10s, and 100s
Sal demonstrates visually how to subtract 3-digit numbers by subtracting ones, tens, and hundreds. Includes a video, transcript, and question and answer section. [3:11]
Khan Academy
Khan Academy: Adding 1s, 10s, and 100s
Sal adds 3-digit numbers by adding ones, tens, and hundreds. Includes a video, transcript, and question and answer section. [3:36]
Math Mammoth
Math Mammoth: Review: Adding and Subtracting Whole Tens
This video goes over how to add and subtract multiples of ten to or from a 2-digit number. [8:14]
Math Mammoth
Math Mammoth: Mental Math: Add and Subtract Multiples of Ten
This video goes over how to add and subtract multiples of ten to or from a 3-digit number. [9:54]
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: Regrouping to Add 1 Digit Number
Demonstrates how to add 35 + 6 using drawings of base ten cubes to represent 1s and 10s and show the regrouping. [4:14]
Khan Academy
Khan Academy: Subtracting a 1 Digit Number With Regrouping
Demonstrates how to solve 35 - 8 using drawings of base ten cubes to show the regrouping of ones and tens. [3:11]
Khan Academy
Khan Academy: Understand Place Value When Adding Ten
Demonstrates how to add two 2-digit numbers, with no regrouping, using drawings of base ten cubes to represent 1s and 10s. [3:16]
Khan Academy
Khan Academy: Subtracting 1s Using Place Value
Demonstrates how to subtract 4 from 46 using drawings of base ten cubes to represent 1s and 10s. [2:45]
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]
Khan Academy
Khan Academy: Strategies for Adding 2 Digit Numbers
Sal goes through multiple strategies for adding 2-digit numbers. [3:15]
CK-12 Foundation
Ck 12: Elem Math: One Step Conversions Between Hundreds Tens and Ones
[Free Registration/Login may be required to access all resource tools.] The video uses place value to determine the number of hundreds given a specific number of ones. The video is followed by a series of practice questions to assess...
Khan Academy
Khan Academy: Estimating Adding and Subtracting 3 Digit Numbers
Use estimation to find reasonable solutions to addition and subtraction problems.