This short video and interactive assessment activity is designed to teach fourth graders about adding and subtracting.

Students will practice adding and subtracting common denominators before advancing to adding and subtracting fractions that do not have common denominators.

Kahn Academy video - How to add and subtract fractions with like and unlike denominators.

This resource includes three tasks surrounding the Common Core Standard 5.NF.2 - Adding and Subtracting Mixed Numbers with Unlike Denominators Using an Open Number Line and Fraction Equivalence. The tasks involves looking at real Maryland snowstorm data and each task builds off the previous task.

This short video and interactive assessment activity is designed to teach fourth graders about adding and subtracting money with pictures in columns.

3rd grade math problem trail lesson plan to practice accurately adding and subtracting multi-digit numbers incorporating physical activity.

This is an interactive assessment and video designed to teach Adding and Subtracting (Numbers up to 20) - Word Problems to first graders.

In this seminar you will continue your learning of rational expressions adding and subtracting them as stand alone problems, as well as in real-world situations  You will continue to use strategies for simplifying complex situations into more solvable situations.StandardsCCSI: HS: Algebra: HSA-SSE.A. Interpret the structure of expressions.CCSI: HS: Algebra: HSA-SSE.B. Write expressions in equivalent forms to solve problems.

This short video and interactive assessment activity is designed to teach fourth graders about adding and subtracting terms (numbers to 100).

This short video and interactive assessment activity is designed to teach fifth graders about adding and subtracting with parentheses.

In this video we explore how to derive the demand for a factor of production based on how productive that factor is and how much additional revenue that factor brings in. Created by Sal Khan.

To add the vectors (x₁,y₁) and (x₂,y₂), we add the corresponding components from each vector: (x₁+x₂,y₁+y₂). Here's a concrete example: the sum of (2,4) and (1,5) is (2+1,4+5), which is (3,9). There's also a nice graphical way to add vectors, and the two ways will always result in the same vector.​​

This short video and interactive assessment activity is designed to teach fourth graders about addition: completing the addition sentence.

The purpose of this task is to study some patterns in a small addition table. Each pattern identified persists for a larger table and if more time is available for this activity students should be encouraged to explore these patterns in larger tables.

This is a task from the Illustrative Mathematics website that is one part of a complete illustration of the standard to which it is aligned. Each task has at least one solution and some commentary that addresses important aspects of the task and its potential use.