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

[1/4 Integer column vertical calculation]
    Question type: Integer multiplication
    Original question: 77777777*99999999
    Solution:
    77777777*99999999 = 7777777622222223
    Column vertical calculation:

													7	7	7	7	7	7	7	7
✖													9	9	9	9	9	9	9	9
												6	9	9	9	9	9	9	9	3
											6	9	9	9	9	9	9	9	3
										6	9	9	9	9	9	9	9	3
									6	9	9	9	9	9	9	9	3
								6	9	9	9	9	9	9	9	3
							6	9	9	9	9	9	9	9	3
						6	9	9	9	9	9	9	9	3
					6	9	9	9	9	9	9	9	3
					7	7	7	7	7	7	7	6	2	2	2	2	2	2	2	3

[2/4 Formula]
    Work: Calculate the value of equation 1+3+5+7+10+13+15+17+19 .
    Question type: Mathematical calculation
    Solution:
          1+3+5+7+10+13+15+17+19
        =4+5+7+10+13+15+17+19
        =9+7+10+13+15+17+19
        =16+10+13+15+17+19
        =26+13+15+17+19
        =39+15+17+19
        =54+17+19
        =71+19
        =90
    Answer:1+3+5+7+10+13+15+17+19=90
[3/4 Formula]
    Work: Calculate the value of equation 2+4+6+8+10+12+14+16+18 .
    Question type: Mathematical calculation
    Solution:
          2+4+6+8+10+12+14+16+18
        =6+6+8+10+12+14+16+18
        =12+8+10+12+14+16+18
        =20+10+12+14+16+18
        =30+12+14+16+18
        =42+14+16+18
        =56+16+18
        =72+18
        =90
    Answer:2+4+6+8+10+12+14+16+18=90
[4/4 Formula]
    Work: Calculate the value of equation 48*49*50*51*52/5 .
    Question type: Mathematical calculation
    Solution:
          48*49*50*51*52/5
        =2352*50*51*52/5
        =117600*51*52/5
        =5997600*52/5
        =311875200/5
        =62375040
    Answer:48*49*50*51*52/5=62375040

Your problem has not been solved here? Please go to the Hot Problems section！