Using ten frames can encourage subitizing, help develop a sense of magnitude, show one-to-one correspondence, build number sense, improve understanding of base ten, and demonstrate strategies for composing and decomposing numbers. Ten frames are a versatile tool for addressing individual state standards, as well as addressing the CCSS. Great for developing number sense within the context of ten. Includes 4 interlocking foam boards with 40 two-color foam pegs.