Curated Video
Using the Commutative and Associative Properties to Add 2-Digit Numbers
In this video, students will learn how to use the properties of addition, such as the commutative and associative properties, to solve addition problems with two-digit numbers. They will also review the value of each digit within a...
Curated Video
Two-Step Word Problems
The video “Two-Step Word Problems” identifies keywords for addition and works through several addition word problems that require two steps to solve.
TED Talks
TED: How fear of nuclear power is hurting the environment | Michael Shellenberger
We're not in a clean energy revolution; we're in a clean energy crisis, says climate policy expert Michael Shellenberger. His surprising solution: nuclear. In this passionate talk, he explains why it's time to overcome longstanding fears...
Curated Video
Regrouping and Carrying
The video “Regrouping and Carrying” explains how to use regrouping and carrying as part of the standard algorithm for adding two- and three-digit numbers.
Curated Video
Estimating
Mr. Addit demonstrates how to estimate by rounding up or rounding down. He then gives examples in which estimating helps solve a division problem.
Curated Video
MAGICAL Indian Math Discovery - Numbers 495 and 6174 (Kaprekar Constants)
The Indian mathematician Dattaraya Ramchandra Kaprekar discovered the number 6174 is reached after repeatedly subtracting the smallest number from the largest number that can be formed from any four digits not all the same. The number...
Curated Video
Review for You: Regrouping
Mr. Addit reviews the method of using regrouping and carrying to add 2, 2-digit numbers and 2, 3-digit numbers. He reviews the method of regrouping and borrowing to subtract 2, 2-digit numbers and 2, 3-digit numbers.
Curated Video
Greater than, Less than, Equal To
Mr. Addit begins a discussion of greater than, less than, and equals and provides examples of their usage. He also explains how to place the proper symbol between sets of numbers.
Kids Academy
Numbers Counting to 100 & 1000 | Math for 1st Grade | Kids Academy
We want to help prevent learning disruptions while school is out by offering families, educators, schools, and districts a 50% discount on all our membership plans: https://bit.ly/2xiePZg When teaching math, number sense is critical for...
Khan Academy
Singapore Math: Grade 3a Unit 2 (part 5)
What a great way to present multiple-digit addition! Sal adds the numbers 2803 and 1443. He draws a chart representing each of the four place values from the problem and then draws "place value buckets” to represent what each number...
Khan Academy
Singapore Math: Grade 3a, Unit 2 (Part 11)
Solving two-step word problems is a great way to build strong critical thinking and creative problem-solving skills. This video showcases three-word problems involving multi-digit addition or subtraction. Sal highlights essential...
Curated OER
Singapore Math: Grade 3a, Unit 2 (part 11)
Solving 2-step word problems is a great way to build strong critical thinking and creative problem-solving skills. This video showcases three word problems involving multi-digit addition or subtraction. Sal highlights important...
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...
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]