(1) 36+42+64+158 =(36+64)+(42+158) =100+200 =300 |
(2) 1600﹣217﹣483, =1600﹣(217+483) =1600﹣700 =900 |
(3) 42×(66﹣400÷25) =42×(66﹣16) =42×50 =2100 |
(4) 163×8+137×8 =(163+137)×8 =300×8 =2400 |
(5) 4200÷25÷4 =4200÷(25×4) =4200÷100 =42 |
(6) 672÷[6×(75﹣67)] =672÷[6×8] =672÷48 =14 |