Idea 7of 23Builds onTen of a place make one of the nextRead a big number in two parts
One more than 99 999
What happens when a counter at 99 999 goes up by 1?
Today you'll discover
- why every 9 turns into a 0
- where the new 1 goes
- how to read 100 000
Think firstA car's kilometre counter reads 99 999
The car goes 1 more kilometre. What does the counter show now?
Decide first, then press Next. Follow the 1 from the ones to the left.
A six-column place-value chart reading 99 999, its hundred thousands column empty. A plus 1 appears under the ones; curved arrows marked 10 to 1 run from each column to the next on its left, and a new row reads 1, 0, 0, 0, 0, 0: 99 999 + 1 = 100 000. Then 100 000 in the chart with the words one hundred thousand. The last step shows a counter at 64 999.
See the whole ideathe big idea and the key word, in one place
The big idea
Adding 1 to 99 999 rolls every 9 over to 0 and makes 100 000, one hundred thousand.
For exampleCounters roll over like this in real life: a car's kilometre counter, a step counter, the points on a pinball machine.
Key word
- one hundred thousand
- 100 000, the number after 99 999; ten ten thousands
Ready to use it?
- Count on past a number that ends in 9s.