Subtraction - With Changing

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Age

3-6

Materials

  1. Unlimited Golden Beads.
  2. Large Number Cards.
  3. At least 2 sets of Small Number Cards.
  4. At least 2 trays and unit pots fro carrying.
  5. An operational mat.
  6. A floor mat.


Preparation


Presentation

  1. This is a group activity. Directress invites the children to take the Large and Small Number Cards from the shelf and to lay out the cards on the floor mat.
  2. Meanwhile, Directress sets up the 'Bank' and lays out the operational mat on the table.
  3. The Directress sets a subtraction question, which involves changing, e.g. 3214-1246.
  4. Directress gives child a tray and asks her to fetch the large number cards and the corresponding beads for 3214.
  5. Child A does that and places the beads on the operational mat with the cards beside it.
  6. The Directress then asks Child B to take away the quantity, 1246.
  7. The child will realize that he does not have enough units to take away when he tries to take away 6 units from the 4 units on the mat.
  8. Then he will be told that he could change one of the Ten Bead Bars on the mat for 10 Golden Beads at the bank.
  9. The 10 Golden Beads exchanged are placed together with the rest on the mat.
  10. The child then takes away 6 units.
  11. The child then tries to take away 4 tens and he will realize that there is none for him to take away.
  12. So, he exchange 1 One Hundred Square for 10 Ten Bead Bars.
  13. He then takes away 4 tens from the Ten Bead Bars on the mat.
  14. The child goes on to try taking away two hundreds from the one hundred left on the mat. He finds that he can't and so he exchanges 1 Thousand Cube for 10 Hundred Squares.
  15. From the Hundred Squares on the mat, the child takes away 2 hundred.
  16. Finally, the child takes 1 thousand from the 2 thousand left on the mat.
  17. The total 1246 taken away are placed on the tray and the corresponding small number cards are also fetched and placed on tray.
  18. Child A then starts to count the number of beads left on the mat.
  19. He brings the beads down to the bottom of the mat as he counts them as in previous exercises and find the total to be 1968.
  20. The corresponding small number cards are fetched and placed beside the beads.


Control Of Error

Directress guided.

Points Of Interest


Purpose

  • Show the children how to 'change' when doing subtraction.


Variation


Handouts/Attachment