Addition & Subtraction
Online Activities for 3rd - 6th Classes
Khan Academy Addition and Subtraction (Third Grade): Watch the videos and then answer the practice questions. For something more challenging, look at Addition and Subtraction in Fourth Grade Maths. You can also register for a free Khan Academy account to record your progress and explore other topics/grades.
That Quiz - Arithmetic: Use this quiz to practice different types of addition and subtraction calculations. You can use the options on the left hand side to make the types of calculations easier or more difficult.