I have just listed a new item on TpT and my website, called Double Bug. It includes some cute colourful posters to help introduce and explain doubles (yes, I am a very "visual" learner and teacher!) and a cute little printable card game to use in groups or a center.
Click here to see it on TpT.
Teaching doubles will help make addition and subtraction easier for your students.
A great way to introduce doubles is to let your students use little mirrors. Give them a small quantity of counters or plastic teddies. Let them hold up a small hand mirror to see how their collection has doubled. Have them count out the new total. Ask your students to write number sentences to match a variety of "doubles" that they create with their mirror.
A great book to read is Two of Everything by Lily Toy Hong (Whitman, 1993) Use it to help introduce the idea of doubles.
I also found these great items on Tpt, by doing a quick search for "doubles"
Leave a comment if you have a great resource for teaching doubles.