Ranking with SUMPRODUCT

Hi!

I'm trying to figure out how a "conditional ranking" is working on a spreadsheet that I'll attach to this thread. I want to learn/understand so I can apply this on different situations, the part that confuses me the most is the "*10^-6".

Basically, there are two formulas on this spreadsheet:

Ranking two criteria
=SUMPRODUCT(--(($C$3:$C$5+$D$3:$D$5*10^-6)>C3+D3*10^-6))+1
Captura de Tela 2021-12-26 ās 23.21.48.png

Ranking three criteria
=SUMPRODUCT(--(($C$10:$C$20+$D$10:$D$20*10^-3+$E$10:$E$20*10^-6)>C10+D10*10^-3+E10*10^-6))+1
Captura de Tela 2021-12-26 ās 23.22.04.png

Could anyone help understand this SUMPRODUCT?