The best way to teach math is with real-life applications. The best way to demonstrate math concepts is with hands-on materials that are multi-sensory. These tools are called manipulatives because kids can touch and interact with them.
They're not just paper and pencil activities or textbook lessons. Math manipulatives include real or play money (for market math), clocks for telling time, fraction bars, pattern blocks, parquetry blocks, peg boards, base ten blocks, Unifix cubes and Cuisinaire Rods. Here are websites with free printable math manipulatives for homemade materials.
Mason has a webpage with dozens of links for free printable math manipulatives, Print pattern blocks, geometry shapes, Base Ten blocks, color tiles, XY blocks and fraction bars. These tools are commonly used in preschool, kindergarten and special needs classrooms, but should be used in all grades to teach geometry, algebra and other maths.
Sparkle Box from the United Kingdom is jam-packed with free math manipulatives and printables. There are free printable PDFs of clock activities for telling time, fraction pies and bars, coins and play money for learning about money math and many free printable math games. Math games include spinners, dice, game board, pieces and accessories, all free printable cut-out activities.
Making Learning Fun has hundreds of free printable math games and manipulatives. This website is organized according to theme, such as Cats, Apples or different children's literature books. Each theme or topic has free printable math lessons, crafts, cut and paste, puzzles and more.
Teacher Resources Galore is huge clearinghouse of educational materials, including free printable math lesson plans. Each math curriculum content area has dozens of free printables listed. Search for the math content area that you are teaching to find what manipulatives you can print. Just click to open the PDF and print.
Jimmie's Collage is a neat homeschool blog with gobs of mom-teacher-made math manipulatives to print.