Greater Than and Less Than Symbols

Date: 05/30/2000 at 09:25:07
From: Angelo Gagliano
Subject: Greater/Less Than

I am assisting my Middle School Son with his Math Homework.

His teacher claims that '> 25' represents greater than 25. I was 
taught that it meant less than. The number that the angle points to 
was always less than and the wide angle was greater than... perhaps 
his teacher erred?

Can you help?

Thank you.

Date: 05/30/2000 at 11:27:03
From: Doctor TWE
Subject: Re: Greater/Less Than

Hi Angelo - thanks for writing to Dr. Math.

No, the teacher is correct, > 25 would be read as "greater than 25." 
You are right, too, when you say "the number that the angle points to 
was always less than and the wide angle was greater than..." In your 
example, the angle 'points to' the 25, so the 25 is less than 
whatever, or in other words, whatever is greater than 25.

Perhaps it would help if we put a number or a variable in front of the 
greater than sign: 50 > 25. Now we can see that the wide angle is 
facing the 50, the larger number.

There's a mnemonic (memory aid) for remembering which way the symbol 
goes. Perhaps your rule is based on this or some variation. The way I 
learned it (with appropriate illustration) was that an alligator - 
which is notoriously hungry - always wants to eat the larger number. 
The symbol, < or > , represents its mouth, with the wide end being the 
open jaw. The alligator should always face the larger number. I guess 
you can modernize it and simplify the drawing by calling it a hungry 
Pac-Man instead.

I hope this helps. If you have any more questions, write back.

- Doctor TWE, The Math Forum
  http://mathforum.org/dr.math/