Simply make the < and > into Pac-man by drawing a circle around them.

Now, say that Pac-man, being the ever-hungry eating machine that he is, always wants to eat the bigger number, so 5 > 3 and so on.

It doesn't get any simpler, and it's easier to remember than which symbol is greater or less than.

Disclaimer: This probably works better if you live in 1986 when they taught me this and Pac-man was still recognized by all and sundry.