Last year we built a small balance beam for free out of a piece of scrap 2×4 and two concrete blocks we salvaged. While it was functional, easy, and cheap, I was really eager to upgrade to something larger this year.
This year I purchased an 8 foot length of 4×4 to use as the balance beam. I cut two 3 foot long pieces of 2×4 and screwed them to the underside of the 4×4 for stability. Then I painted the whole thing with some white paint that I had left over from another project.
Once the white paint was dry, I measured out and made a mark on the beam every 3 inches. I then used a stencil to paint a number line.
Starting in the middle with 0 and working my way towards the edges, the number line ranged from 15 to -15 when complete.
The children can use it as a standard balance beam, just walking across it.
Or they can stand on the zero mark and move along the line based on the math questions I throw at them.