Material Description:
A box with three compartments, or three different boxes each containing five identical wooden tablets. Each set of tablets is made of a different wood, with it’s own natural colour, so the tablets in it are visually distinct from the ones in other boxes, one set are light in weight, another medium and the third are heavy. Traditionally they differed by ten grams, sometimes this difference differs depending on the manufacturer.
A blindfold
Presentation:
- Bring the tray containing the extreme light and heavy sets to two chowkis and place it on a cloth on the floor
- Introduction – Contrasting Weights
- Place the tablets into two separate piles at the left and right edge of the chowki or put all the tablets randomly onto the chowki
- To indicate that they are different in weight was well as colour, lightly place one on the tips of your upturned hands fingertips
- Place one tablet in the other hand, close your eyes, have the arms free and the back straight
- Gently and slowly allow one arm to go down to feel the weight and then move both arms simultaneously, mirroring the action of pan scales
- Put both tablets back on the chowki
- Repeat a few times with tablets of the same and different weights
- Put the tablets in the child’s and invite her to imitate
- Sorting
- Mix light and heavy tablets into two piles and put each to the left and right of the chowki
- Wear the blindfold
- Pick up the top two tablets from each pile and judge the weight as above
- If the tablets are identical put together, separate contrasting tablets into two piles in the centre of the chowki
- Continue to take tablets in the same manner until another pair is found
- Remove the blindfold and check both piles of tablets and invite the child to do the same
- Put the pair at the far middle of the table
Exercises:
- With eyes closed complete the activity
- Sort separating the heavy from the medium
- Sort separating the light from the medium
- Sort separating the heavy from the medium and light
Language:
“Light” – “Heavy”; comparatives and superlatives
Criteria of Perfection (Control of Error):
- The colour of the wood
Direct Aim:
- Refinement of the baric sense
Age at Presentation:
Three and a half to four years
Footnote:
- When judging weight move downwards first to gauge the weight without the effect of pulling against gravity
- At this age the child is attracted towards the experience of sensorially judging weight, later she will be intellectually attracted; this exercise builds the Mathematical Mind
- Later introduce pan-scales to compare the weight of objects in the environment