1+2+…… +100 = 5050; then 51 + 52 + +How much is 100?
1+2+3+...50=(1+50)+(2+49)+(3+48)+...(25+26)=51*25=1275
51+52+…… +100=5050-1275=3775
What does (- 1 / 2) ˉ 1 Equal
-2
1 () () times () equals () () 52, and the number 9 appears only once
1963*4=7852
Please refer to