Dynamic Operations in the Decimal System

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Age

4-7

Materials

  • Golden bead material
  • Large and small numeral cards
  • Symbol cards for the operations
  • Problem cards for each operation

Preparation

This is an individual presentation.

Presentation

The Change Game: 

  1. A large quantity is placed on the tray and the child is invited to count it.
  2. Beginning with units, the child counts, but is stopped at 10.
  3. Ten units cannot remain loose; they must be exchanged for a ten-bar.
  4. The ten beads are exchanged for one ten-bar from the bank.
  5. The child continues counting units and placing the correct large numeral cards on the tray.
  6. So on to thousands. The cards are arranged and read.

Addition:

  1. The directress reads a problem card. The child performs each command as it is read.

Subtraction:

  1. The directress reads a problem card. The child performs each command as it is read. 
  2. The directress presents the thousand cube and wants to take away 1 unit.
  3. This may be symbolized with the large and small numeral cards for emphasis.
  4. How can this be done? The thousand is changed to 10 hundreds.
  5. Now can we take away one unit? Not quite yet. Continue on until one unit can be taken away.
  6. The remaining quantity is counted and represented with small cards.

Multiplication:

  1. As for addition problem cards are prepared.

Division:

  1. As with static division the child sets about distributing.
  2. When he finds that he doesn't have enough for one hierarchy to go around, he must exchange for a lesser hierarchy.
  3. When there is a remainder, the corresponding small numeral cards are brought and placed after a small card with the initial r to the right of the result.

Control Of Error

The directress.

Points Of Interest

Purpose

  • To exchange equal quantities of different hierarchies
  • To reinforce the rule: only 9 units can remain loose
  • To reinforce knowledge of the composition of each hierarchy (ten tens=100)
  • To realize that one unit revolutionizes a large quantity.
  • To further understand the concept of addition, subtraction, multiplication, and division

Variation


Links


Handouts/Attachments