Now that Eon sees numbers as places on the line, a rule jumps out: order matters. The numbers go 0, 1, 2, 3, 4… — never 0, 3, 1, 4. Each step to the right adds one, in a strict order.
Comparing two places
Eon's dad picks two numbers — 8 and 2 — and asks which is bigger. Eight, because its place is further right. So we say:
two is less than eight.
Meet the < sign
But mathematicians don't write that out in words — they use a symbol: <. Eon's dad describes it perfectly: it's a shape that's wide on one side and comes to a single point on the other — almost like a little open mouth.
Here's the trick that makes it foolproof:
The wide-open mouth always faces the bigger number. The point aims at the smaller one.
So 2 < 8 reads "two is less than eight" — the mouth opens toward the 8.
A challenge — and a lesson in being wrong
Then comes practice: 4 and 10, fill in the sign. In the middle of it, Eon's dad slips up and says the wrong number — then catches himself and says something worth remembering:
"Admitting that you're wrong is good. You have to admit you're wrong in order to improve."
He fixes it: 4 < 10 — four is less than ten, because 4's place is to the left of 10's. (A nice reminder that mistakes aren't failures — they're how learning works, even for the teacher.)
Try it
Fill in the sign: 3 ☐ 9. (Three is further left, so it's smaller: 3 < 9 — the mouth opens toward the 9.)