题目
计算下面各题,能简算的要简算。
①79+113+21+87
②2600÷25÷4
③(169+314)-315÷9
④28.63+15.4-8.63
⑤53×36+36×47
⑥4.88-2.34+5.12-1.66
答案:①79+113+21+87 =79+21+(113+87) =100+200 =300; ②2600÷25÷4 =2600÷(25×4) =2600÷100 =26; ③(169+314)-315÷9 =483-35 =448; ④28.63+15.4-8.63 =28.63-8.63+15.4 =20+15.4 =35.4; ⑤53×36+36×47 =(53+47)×36 =100×36 =3600; ⑥4.88-2.34+5.12-1.66 =4.88+5.12-(2.34+1.66) =10-4 =6。