Cool Math
Coolmath: Coolmath4kids: Printable Flash Cards
Find here flashcards for addition, subtraction, multiplication, and division for printing off and coloring.
NumberNut
Number Nut: Subtraction: Subtracting From Three Digit Numbers
Explains how to subtract from three-digit numbers, with or without regrouping.
NumberNut
Number Nut: Subtraction: 3 Digit Numbers
A brief lesson on subtracting from three-digit numbers that includes detailed examples, rules, and further explanation of borrowing.
Other
Sumdog Teacher Portal: One More, One Less
This engaging lesson plan introduces students to basic addition and subtraction by adding or subtracting one. Teachers can create a free Sumdog account and usernames for their students to practice the skills through online learning games.
Better Lesson
Better Lesson: Cheerful Shoppers
Second graders love to shop! Students will use their own shopping list to compose a word problem using addition and subtraction with and without regrouping, in order to help them better understand how to problem solve.
Books in the Classroom
Carol Hurst's Children's Literature Site: Computation and Picture Books
This sample chapter from Hurst's book Picturing Math is an excellent resource for using picture books and activities for learning computation.