The number line

In your book, Maths Mela (Chapter 4), you place 4-digit numbers on a number line. One line goes from 1000 to 1100, with a mark every 10: 1000, 1010, 1020, and so on. Where does 1043 go? It is more than 1040 and less than 1050, so it sits between those two marks, a little closer to 1040. 1069 sits between 1060 and 1070, and 1084 between 1080 and 1090.

On a longer line from 2000 to 2500, marked every 100, the numbers 2025, 2080, 2175 go in this order, from the 2000 end towards the 2500 end: 2025 is nearest to 2000, and 2175 is between 2100 and 2200.

The book asks which numbers lie between 2226 and 3226. A number lies between them if it is bigger than 2226 AND smaller than 3226. 2236 is bigger than 2226 (3 tens beats 2 tens), so it is in. 3126 and 3216 are smaller than 3226, so they are in. But 2216 is smaller than 2226, and 3236 and 3316 are bigger than 3226, so they are out.

Here is the book's Challenge. Strictly between 700 and 800 (not counting 700 or 800) there are 99 numbers: 701 up to 799. Strictly between 7000 and 8000 there are the numbers 7001 up to 7999. That is 999 numbers.