Challenge Level

How many odd numbers are there between $3$ and $11$?

How many odd numbers are there between $4$ and $11$?

What do you notice? Can you explain your observation?

Can you find any other pairs of numbers which have this same number of odds between them?

Can you find a pair of numbers which have four odd numbers between them?

Can you find another pair of numbers which have four odds between them? And another pair?

How would you find a pair of numbers that have five odds between them? Six odds?

How would you explain to someone else how to find a pair of numbers that have a certain number of odds between them?