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]
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: Missing Numbers in Addition and Subtraction
Demonstrates how to find missing numbers in addition and subtraction equations within 100. [5:44]
Khan Academy
Khan Academy: Repeated Addition: Haircuts
Demonstrates how to use repeated addition to count how many haircuts Rafael gets in one year. [2:09]
Sophia Learning
Sophia: Even Numbers: Lesson 2
This lesson shows even numbers, or numbers which can be evenly divided by two. It is 2 of 13 in the series titled "Even Numbers."
Sophia Learning
Sophia: Even Numbers: Lesson 3
This lesson shows even numbers, or numbers which can be evenly divided by two. It is 3 of 13 in the series titled "Even Numbers."
Sophia Learning
Sophia: Even Numbers: Lesson 4
This lesson shows even numbers, or numbers which can be evenly divided by two. It is 4 of 13 in the series titled "Even Numbers."
Sophia Learning
Sophia: Even Numbers: Lesson 7
This lesson shows even numbers, or numbers which can be evenly divided by two. It is 7 of 13 in the series titled "Even Numbers."
Sophia Learning
Sophia: Even Numbers: Lesson 1
This lesson shows even numbers, or numbers which can be evenly divided by two. It is 1 of 13 in the series titled "Even Numbers."
Khan Academy
Khan Academy: Subtracting 2 Digit Numbers Without Regrouping 1
Demonstrates how to subtract 23 from 65 by first breaking each number into tens and ones. [2:36]