An Elegant and Insightful Direct Combinatorial Proof
of the Arithmetical Identity 4+5=2+7

There are no trivial theorems,
only trivial mathematicians (those who believe that there exist trivial
theorems). Being a non-trivial mathematician myself, I will present a
new, elegant, and very insightful direct combinatorial proof of the
seemingly (to most people)
"trivial"  arithmetical theorem that states that four plus five equals
two plus seven.  More important, the methodology should extend to give
insightful direct combinatorial proofs of even deeper identities, like
(4+6+200+6+50)+(3+10+30+5)=300+4+10.