简算4.9+0.1﹣4.9+0.110.78﹣(2.78+3.693)99.99×22.22+33.33×33.34(2.5×2.5+2.5×2.5+2.5×2.5+2.5×2.5)×8.
请用脱式计算 。72-3×8÷6 3600÷(20-5) (450+27) ÷(21-18)
请你口算。0.38+0.06= (155+20)-65= 64.2+5.7= 543-27-73=0.97-0.09= 12.8-9.86= 17.05-4.58 = 9800÷25÷4=3.5+0.6=4.1 5-0.15= 4.35+5.36= 99×66+66= 0.81+0.09= 0÷78= 50-20÷5= 35×25×4=
计算(730-230)÷10+42 24÷(75-67)×60 450-(37.7+83.25)
计算。309×28= 567÷28= 7200÷40= 578÷28=
估算。83÷9≈ 79×30≈ 178÷6≈ 51×68≈