Number puzzles and multiple towers

[Jjparker6]

My son has a math page: Puzzle 1 states: This number is less than 30.

How do I help him with figuring this problem out?

 

[Deleted member 4993]

My son has a math page: Puzzle 1 states: This number is less than 30.

How do I help him with figuring this problem out?

If that's all the hint is given - the answer would be x < 30