,如果四年级人数是180人,那么五年级人数是人。
×60= × = 0.36× = 15:20=
÷2= 6÷ = 0.56÷ = :0.75=
0.125×1.7×8= 2-0.53=
2.9×3÷2.9×3=
12: = 7÷1.4=
①12.4+5.6= ②640÷8= ③ × = ④16÷ =
⑤5³= ⑥ ⑦ ⑧