Curated Video
Finding the Area of Polygons by Decomposing
In this video, the teacher explains how to find the area of polygons by breaking them down into familiar shapes such as triangles, rectangles, parallelograms, and trapezoids.
Curated Video
Adding Numbers to 1000 with Regrouping
In this lesson, students will learn how to add numbers up to 1000 using regrouping. They will understand the concept of place value and how to combine numbers to find their total.
Curated OER
Singapore Math: Grade 3a, Unit 2 (Part 3)
Using three-digit numbers, this video discusses the process used to add and subtract with regrouping. The instructor also focuses on determining when and when not to regroup. It describes precisely what is happening when a problem...
Khan Academy
Khan Academy: Adding 3 Digit Numbers
Learn to use regrouping, or carrying to add 709+996, 373+88, and 149+293.
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]
CK-12 Foundation
Ck 12: Elem Math: Overview of Addition (Sums to 1,000)
[Free Registration/Login may be required to access all resource tools.] Video demonstrating how to add two 3-digit numbers vertically with no regrouping. [1:04]