题目
计算下面各题,能简算的要简算。
① × ÷ ② × - ÷ ③4.8×( + - ) ④ + ÷ ⑤ ÷0.4+ × ⑥ ÷[( - )× ]
答案:① 1526 × 56 ÷ 913 = 1526 × 56 × 139 = 2536 ② 815 × 34 - 725 ÷ 145 = 25 - 110 = 310 ③4.8×( 34 + 12 - 23 ) =4.8× 34 +4.8× 12 -4.8× 23 =3.6+2.4-3.2 =2.8 ④ 34 + 14 ÷ 32 = 34 + 14 × 23 = 34 + 16 = 1112 ⑤ 47 ÷0.4+ 37 × 52 = 47 × 52 + 37 × 52 =( 47 + 37 )× 52 = 52 ⑥ 415 ÷[( 58 - 14 )× 815 ] = 415 ÷[ 38 × 815 ] = 415 ×5 = 43