SE 1.05Red Rods
The child grades ten red rods from 10 cm to 1 m long.
Presentation
- 1
Invite the child and unroll a long rug near the rods.
- 2
Show how to carry a rod: stand beside it, hold it with one hand near each end, and carry it upright or level at the side so it does not hit others.
- 3
Bring the rods one at a time and place them at random on the rug.
- 4
Choose the longest rod and place it at the top of the rug.
- 5
Find the next longest, place it below the first with the left ends aligned, and continue until all ten form a stair.
- 6
Run your hand along the left ends to show they are even, then walk your hand down the steps.
- 7
Place the shortest rod beside each step to show each step is the length of the shortest rod.
- 8
Return the rods to the stand one at a time.
Extensions, easiest to hardest
- Grade the rods with the ends aligned at the right.
- Arrange the rods in a pattern such as a maze or a spiral, keeping the order.
- Grade the rods with eyes closed, measuring each by running a hand along it.
- Bring rods from across the room in order.
- Use the shortest rod to measure each of the other rods.
Control of error
A rod out of order leaves a step that is not the length of the shortest rod; the shortest rod laid on that step is too long or too short.
Ready to move on when the child…
- Carries the rods safely and builds the stair in order
- Aligns one set of ends and checks the steps
- Corrects errors unaided
Guide note
Watch for children swinging rods. Show the carry again and require a clear path before carrying.