I love making manipulatives instead of having to buy them! Love the abacus idea .
Planet Smarty Pants: Hands On Math Tools: An Abacus
Learn how to make and use a simple DIY abacus. - so cute - a pocket abacus!
Abacus Classes In Jaipur- Join LAP(Learners Abacus Programme) for Abacus education, training and maths learning and understand the kids psychology by Mental Arithmetic Abacus. It's a part of Shrishti Education Group.
How to Use an Abacus: 11 Steps (with Pictures) - wikiHow
The Abacus - How to Use This Ancient Wonder