Numbers 0 to 100
Primary 2 · Mathematics
Numbers 0 to 100
Lesson 2 of 3
13 min
Gatete pours a big pile of beans onto the mat. So many!
He starts counting one by one and loses his place. Twice.
Then he has a clever idea. What if he puts the beans into little groups of ten?
Gatete makes groups of ten beans. He calls each group a bundle.
He makes one bundle. Two. Three. Four. Then he stops, because only 7 beans are left. That is not enough for another bundle.
So Gatete has 4 bundles of ten and 7 loose beans.
4 bundles is 40 beans. Add the 7 loose ones: 40 and 7 is 47.
Look at 47 again. It has two digits, and each digit has its own job.
The 4 on the left counts the tens (the bundles).
The 7 on the right counts the ones (the loose beans).
So 47 means 4 tens and 7 ones.
63 is 6 tens and 3 ones. Six bundles, three loose. 60 and 3 makes 63.
28 is 2 tens and 8 ones. Two bundles, eight loose. 20 and 8 makes 28.
90 is 9 tens and 0 ones. Nine full bundles and nothing left over. That empty space is why we write a 0 in the ones place.
Now go the other way. Umutoni has 5 bundles of ten sticks and 6 loose sticks.
5 tens, so write a 5 in the tens place.
6 ones, so write a 6 next to it, in the ones place.
Umutoni has 56 sticks.
Careful! 5 tens and 6 ones is not 11. Never add the two digits together. The 5 is standing for fifty.
38 is 3 tens and 8 ones.
83 is 8 tens and 3 ones.
The very same two digits — but 83 is much bigger, because it has eight bundles. The digit on the left changes everything.
Tip
Left is big, right is small
The digit on the left counts the bundles of ten. The digit on the right counts the loose ones.
Whisper it as you read: "Six... tens. Three... ones. Sixty-three."
Try each one on your own first. Draw the bundles if it helps!
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