①612÷18+780÷30
②2.5×32×12.5
③5÷(0.5+)×
④
⑤()
⑥16×+8×+12÷25
甲店
(49元/个)
超过10个按八折
乙店
买5个送1个
= 2.4×5= = 0.32=
= = =