①305×29=
②590×700=
③※187×46=
④※353÷17=
①800÷25
②640÷40
=400+193-3
=593-3
=590
=645-(378+22)
=645-400
=245
15×60= 640÷40= ÷ = 398÷202≈ 6.9÷0.1=
1.05-0.65= 0.8×125%= 5- = ÷6= 910-430=