Overview: 4 questions will be solved this time.Among them
           ☆3 arithmetic calculations
           ☆1 integer calculations

[1/4 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
[2/4 Formula]
    Work: Calculate the value of equation 12+23+34+45+56+67+78+89+91 .
    Question type: Mathematical calculation
    Solution:
          12+23+34+45+56+67+78+89+91
        =35+34+45+56+67+78+89+91
        =69+45+56+67+78+89+91
        =114+56+67+78+89+91
        =170+67+78+89+91
        =237+78+89+91
        =315+89+91
        =404+91
        =495
    Answer:12+23+34+45+56+67+78+89+91=495
[3/4 Formula]
    Work: Calculate the value of equation 98+197+2996+39995+499994+5999993+69999992+799999991 .
    Question type: Mathematical calculation
    Solution:
          98+197+2996+39995+499994+5999993+69999992+799999991
        =295+2996+39995+499994+5999993+69999992+799999991
        =3291+39995+499994+5999993+69999992+799999991
        =43286+499994+5999993+69999992+799999991
        =543280+5999993+69999992+799999991
        =6543273+69999992+799999991
        =76543265+799999991
        =876543256
    Answer:98+197+2996+39995+499994+5999993+69999992+799999991=876543256
[4/4 Integer column vertical calculation]
    Question type: Integer multiplication
    Original question: 8*12345679011
    Solution:
    8*12345679011 = 98765432088
    Column vertical calculation:

																8
✖						1	2	3	4	5	6	7	9	0	1	1
																8
															8
														0
												7	2
											5	6
										4	8
									4	0
								3	2
							2	4
						1	6
						8
						9	8	7	6	5	4	3	2	0	8	8

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