Overview: 3 questions will be solved this time.Among them
           ☆3 arithmetic calculations

[1/3 Formula]
    Work: Calculate the value of equation 9+99+999+9999+99999 .
    Question type: Mathematical calculation
    Solution:
          9+99+999+9999+99999
        =108+999+9999+99999
        =1107+9999+99999
        =11106+99999
        =111105
    Answer:9+99+999+9999+99999=111105
[2/3 Formula]
    Work: Calculate the value of equation 1+2+3+4+5+6+7+8+9+10+9+8+7+6+5+4+3+2+1 .
    Question type: Mathematical calculation
    Solution:
          1+2+3+4+5+6+7+8+9+10+9+8+7+6+5+4+3+2+1
        =3+3+4+5+6+7+8+9+10+9+8+7+6+5+4+3+2+1
        =6+4+5+6+7+8+9+10+9+8+7+6+5+4+3+2+1
        =10+5+6+7+8+9+10+9+8+7+6+5+4+3+2+1
        =15+6+7+8+9+10+9+8+7+6+5+4+3+2+1
        =21+7+8+9+10+9+8+7+6+5+4+3+2+1
        =28+8+9+10+9+8+7+6+5+4+3+2+1
        =36+9+10+9+8+7+6+5+4+3+2+1
        =45+10+9+8+7+6+5+4+3+2+1
        =55+9+8+7+6+5+4+3+2+1
        =64+8+7+6+5+4+3+2+1
        =72+7+6+5+4+3+2+1
        =79+6+5+4+3+2+1
        =85+5+4+3+2+1
        =90+4+3+2+1
        =94+3+2+1
        =97+2+1
        =99+1
        =100
    Answer:1+2+3+4+5+6+7+8+9+10+9+8+7+6+5+4+3+2+1=100
[3/3 Formula]
    Work: Calculate the value of equation 2+10+18+26+34+42+50+58 .
    Question type: Mathematical calculation
    Solution:
          2+10+18+26+34+42+50+58
        =12+18+26+34+42+50+58
        =30+26+34+42+50+58
        =56+34+42+50+58
        =90+42+50+58
        =132+50+58
        =182+58
        =240
    Answer:2+10+18+26+34+42+50+58=240

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