In my last Little Hands-on 123s post, I talked about using Duplos to make Montessori number rods.
The traditional rods can be used to introduce addition facts to ten. The Duplo version can be used for addition facts up to your longest rod. The longest rod in the photo is five, but hopefully you have more Duplos or Legos than we do and can go all the way up to ten!
I'll present for the addition facts to make a five rod:Move the five rod down and place the 4 rod (it's backwards in the photo - I put the 1 first but should have put the 4 first) up against it. Then place the one rod against the four rod so it is equal to the five rod. Run your finger along the two rods and say, "four plus one equals five." Then move the three rod under the four rod and place the two rod next to it (still backwards in the photo). Run your finger along that row and say, "Three plus two equals five."The Montessori table number rods comes with two sets so you can show the cummutative law of addition (that the order of the addends doesn't matter). If you had enough rods, you can proceed to put a two rod below the three rod and line up a three rod next to it. Then run your finger along that row and say, "Two plus three equals five." Now place the one rod below the two rod and line up the four rod next to it. Run your finger along this last row and say "One plus four equals five." Thus demonstrating the cummutative law of addition. If you didn't have enough rods, just remove the rods you placed and repeat under the five, this time in the order shown in the photo.
You can do this presentation of addition facts with any of the rods. In the photo above, I show it with the four rod.
Another use of the number rods is to teach one less than and one more than, as well as two less than and two more than.Choose a rod, lets say the 4 rod and show it to your child, asking her to name the rod. Then ask her to find a rod that is one less than the rod you are holding. Once she can do one more and one less with ease, for any number rod you choose, begin to ask for a rod that is two less than or two more than.