Mathematical Understandings
Our students are deeply focussing on understanding place value.
It is often described as knowing the value of a digit in various positions in a number…
But it is more than knowing the 5 in 15 020 is in the thousands place. It is also being able to rename a number in terms of its total of tens, hundreds, thousands etc.
Renaming numbers allows us to be so much more efficient with our calculations.
For example: The number 15 020 could be written as …
Being able to think of this number in all these ways means I can easily subtract one hundred to say I have 149 hundreds and 2 tens (14 920).
Try these
How many different ways could you describe 362 046?
What is 100 less than this number?
How many tens are there now?
What if you add 5000 more tens, how many thousands are there now?
Some cultures use these principles whilst using an abacus on its side to add or subtract easily.
To save space this abacus has been reduced to have 5 beads representing one on the top portion.
The number shown is one hundred and eighty two ones, or 18 tens and 2 ones.
Can you see how I worked that out?
Your turn. What would this number be?
How many hundreds are there? How many thousands are there?
I have a pocket sized version to show you how it works, just drop in.
Stephanie van der Schans, AST/Numeracy.