Tính nhanh a) 32.47+32.53+37.7+80.3+47.3 b) 113.38+113.62+87.62+87.38 c)123.456.321-256.444 d)43.37+93.43+57.61+69.57

Question

Tính nhanh
a) 32.47+32.53+37.7+80.3+47.3
b) 113.38+113.62+87.62+87.38
c)123.456.321-256.444
d)43.37+93.43+57.61+69.57

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Orla Orla 4 years 2020-11-24T22:17:17+00:00 1 Answers 55 views 0

Answers ( )

  1. giahung
    0
    2020-11-24T22:19:03+00:00
    Reply

    Giải thích các bước giải:

    a) $32.47+32.53+37.7+80.3+47.3$
    $=(32.47+32.53)+37.7+80.3+37.3+10.3$
    $=32.100+37(7+3)+.3(80+10)$
    $=3200+37.10+3.90$
    $=3200+370+270=3840$
    b)$ 113.38+113.62+87.62+87.38$
    $=113(38+62)+87(62+38)$
    $=113.100+87.100$
    $=(113+87).100=200.100=20000$
    c)$123.456+456.321-256.444 =456.(123+321)-256.444$
    $=456.444-256.444$
    $=444(456-256)=444.200=88800$

    d)$43.37+93.43+57.61+69.57=43(37+93)+57(61+69)$
    $=43.130+57.130=130(43+57)=130.100=13000$

     

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