Question

123+127+131+135+139+143怎样才能简便运算

Answer 1

123+127+131+135+139+143 简便运算
= 123+127+131+139+135+145 -2
= 250 + 270 + 280 - 2
= 250 + 550 - 2
= 800 - 2
= 798

Answer 2

123+127+131+135+139+143
=130-7+130-3+130+1+130+5+130+9+130+13凑成平均数130
=130*6 -7-3+1+5+9+13
=780+18
=798

Answer 3

可以先算个位数，比如3+7接着1+9后面带上3+5，可以凑10的先相加，再加十位数加百位数就可以了

Answer 4

120＋120＋130+130+130+140+3+7+1+9+3+5
=770+10+10+8
=798