Number Rods and Cards-Montessori

The Number Rods expose students to the concept of measurement. Instead of looking at two rods and saying, “this one is longer,” now the student is able to actually quantify exactly how much longer. While this might seem like a rather intuitive skill, it actually takes a fair bit of practice to be able to judge and compare quantities. The Number Rods are introduced to students of about four years of age, once the student has mastered the Red Rods and has expressed interest in the Number Rods.
MATERIALS
10 wooden rods coloured red and blue.
Each successive rod is bigger by 10cm.
A set of number cards from one to ten kept in a separate box.
A floor mat.
Age :4
PRESENTATION 1
Begin the work cycle.
Ask the child to lay out a floor mat.
The child carries the rods to the mat holding them in the same manner as with the red rods.
Tell the child that the red sections should be at the left-hand side of the mat.
As the child to place down the rods in a random but parallel arrangement on the mat, as though they are ready to be built.
Show the child how to lay the number cards out at the bottom of the mat, in random order.
Invite the child to count the rod closest to him.
He should locate the matching number tablet.
He places the matching number on the end of the rod in an upright position facing you.
Alternatively, invite the child to pick a number tablet, read it and match it against its corresponding rod.
The child continues until all the ten tablets are paired with their corresponding rods.
When you get to the number ten, introduce the child to this number.

PRESENTATION 2
Ask the child to build a stair with the number rods. The number symbols should be spread out in a random arrangement at the bottom of the mat.
Ask the child to count the first rod and then to match the corresponding number symbol to it.
He places the matching number on the end of the rod in an upright position facing you.
The child continues until all the ten tablets are paired with their corresponding rods in a stair formation.

PRESENTATION 3
Once the child is quite familiar with this work tell him you are going to show him something new: COMPOSITION WITH THE NUMBER RODS.
Let the child build and match the number rods as in presentation 2
Isolate the ten Rod.
Similarly, isolate the nine-rod and bring it in front of the ten-rod leaving a small gap between the two rods.
Align them exactly on the left-hand side.
Ask the child “ which rod do we have to put in here to make them the same length?” – indicating the space to the right of the nine rod.
When the child selects the unit rod, place it and its tablet on the right end of the nine rod.
Count the nine rod from left to right and continue with the one rod, calling it “ten”.
Then state the combination saying, “nine and one makes ten” touching the appropriate rods while speaking
Repeat the entire process with the 8 and 2 rod, then the 7 and 3 rod, and then the 6 and 4 rod.
Lastly, two 5’s are shown to make 10 by aligning the 5-rod with the others on the left, and then by flipping the rod over so that it aligns with the others on the right.
In the same way, the child combines two rods to make up the length of the nine-rod, and then the eight-rod and so on down to the unit rod which of-course can not be made up with different rods.

PRESENTATION 4
The child can now be shown DE-COMPOSITION with the number rods
Set aside one of the combinations, and explain the subtraction saying, “ten take away three leaves seven” touching the appropriate rods as you speak. It is simpler when there are no number tablets on the rods at this point.
The child performs a subtraction for each of the combinations.
PRESENTATION 5
As the child gains more experience, you can then show him on a blank piece of paper how to record his answers
.
As you write each number so you refer to the number rods.
Explain what the symbols mean and if necessary do a three period lesson on the meaning of the symbols.
Show the child how to record his answer.
Direct Aim:
To give the child a sensorial impression of quantity
To be able to name in succession the qualities

CONTROL OF ERROR
The quantities on the rods are fixed so this will act as a control of error.
The colours of the rods.
Ability to measure by smallest unit.
Visual: the bands of color and the graded length of the rods.