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The aim is of this activity is to learn the estimation of numbers.
We will need a spike abacus with at least five spikes.
Before we begun create a table with following head.
Now selects a five digit number. For example 38759.
To represent this number on the abacus leave the 9 beads in the one spike.
Remove 4 beads from the Ten spike. Remove 2 beats from the Hundred spike.
Remove 1 bead Thousand spike and finally remove 6 beads from the Ten thousand spike.
The abacus now represents 38759. Now let�s round of 38759 to its nearest
tens which are 38760. Removes all the beads form one spike and add
1 bead to the Ten spike. The abacas now represent 38760.
Let�s round of 38760 to the nearest hundreds which is 38800.
Remove all beads form ten spike and add 1 bead to hundred spike.
The abacus now represents 38800. Finally lets 38800 to the nearest thousands
which is 39000. Remove all the beads from the hundred spike
and add 1 bead form the thousand spike. The abacus now represents 39000.
Try this exercise with these different numbers and represent them on abacus noting down your
answer in the table as before.