Bài 1 : Tính nhanh A, 66.25+5.66+66.14+33.66 B, 35.23+35.182-35.94 C, 27.121-87.27+73.24 D, 125.98

2 bình luận về “Bài 1 : Tính nhanh A, 66.25+5.66+66.14+33.66 B, 35.23+35.182-35.94 C, 27.121-87.27+73.24 D, 125.98”

1. a) 66.25+5.66+66.14+33.66

   = 66. ( 25+5+14+33)=66.77=5082

   b) 35.23+35.182-35.94

   =35.(23+182-94)= 35.111=3885

   c) 27.121-87.27+73.24

   =27.(121-87)+73.24= 27.34 +73.24=918+1752=2670

   d) 125.98-125.26-52.25

   = 125. ( 98-26) -52.25=125. 72-52.25= 25.5.72-52.25= 25.( 360-52)=25.308=7700

   e) 136.23+136.17-40.36

   = 136. ( 23+17)-40.36= 136.40-40.36=40 .(136-36) =40.100 =4000

   g) 19.27+47.81+19.20

   = 19.( 27+20)+47.81= 19.47+47.81=47.(19+81)=47.100=4700

   h) 29.87-29.23+64.71

   = 29.( 87-23)+ 64. 71= 29.64+64.71= 64.( 29+71) =64.100=6400

    

   Trả lời
2. Gui

   #T

   a) 66.25+5.66+66.14+33.66

   = 66.(25+5+14+33)

   =66.77

   =5082

   ___________________________

   b) 35.23+35.182-35.94

   = 35.(23+182-94)

   = 35.111

   =3885

   ____________________

   c)27.121-87.27+73.24

   = 27.(121-87) + 73.24

   =27.34+ 73.24

   =918+1752

   =2670

   _________________

   d) 125.98-125.26-52.25

   = 125.[98+(-26)]-52.25

   =125.72-52.25

   =9000-1300

   =7700

   ______________________

   e) 136.23+136.17-40.36

   = 136.(23+17)-40.36

   =136.40-40.36

   =5440-1440

   =4000

   ______________________

   g) 19.27+47.81+19.20

   =47.81+19.(27+20)

   = 47.81+19.47

   =3807+893

   =4700

   ___________________________

   h 29.87-29.23+64.71

   = 29.(87-23)+64.71

   =29.64+64.71

   =1856+4544

   =6400

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