Calculation 0.1 + 0.2 + 0.3 + ····· + 9.8 + 9.9 + 10 + 9.9 + 9.8 + 9.7 + ······· + 0.2 + 0.1

Calculation 0.1 + 0.2 + 0.3 + ····· + 9.8 + 9.9 + 10 + 9.9 + 9.8 + 9.7 + ······· + 0.2 + 0.1

Divide it into two parts and divide it by 10
(0.1+9.9)*100/2+(0.1+9.9)*100/2+10=1010