Let’s start from the basics. In arithmetic there are nine numbers and a 0. All the numbers are made using these. We need to understand the Place value of these numbers.
We count numbers in groups of 10. Each place has a value of 10 times the place to its right.
Ten Units make a 10
Ten Tens make a 100
Ten Hundreds make a 1000 and so on…
In any number its value depends on its position/place.
In the number 2583: Value of 2 is 2000; 5 is 500; 8 is 80 and 3 is 3.
10 s: Group of 10 units/ones.
100s: Group of 10 tens
1000s: Group of 10 hundreds
10000: Group of 10 thousands
Ten Point Circle
If you look at the circle closely you will notice that the opposite numbers add to 10 (5 will add to itself and make 10)
Our number system is based on the number 10 and proceeds in cycles of 10 e.g. 10, 20, 30 and so on. The reason behind this is that compared to the other numbers; ‘10’ is a very easy number to handle.
It is important to know the five pairs of numbers that add up to 10:
1 + 9 = 10,
2 + 8 = 10,
3 + 7 = 10,
4 + 6 = 10,
5 + 5 = 10.
Now let’s try something on the number circle. Why not fill it with more numbers.
Continuing around the circle we put 11 after 1; 12 after 2 and so on.
Looking at this circle you will notice that
If you add any number with the opposite pair it gives a multiple of 10.
Try any combination and you will always get a multiple of 10.
This circle can be used for addition or subtraction, just as we use a number line.