Khan Academy (English - US curriculum)
Math by grade
Eureka Math/EngageNY
4th grade (Eureka Math/EngageNY)
Module 5: Fraction equivalence, ordering, and operations
Topic D: Fraction addition and subtraction
Adding fractions with like denominators
Adding fractions with like denominators
Sal adds 3/15+7/15.
License: CC BY-NC-SA by Khan Academy