1.
口算。
7×0=
21×4= | 50×9= 60×8= | 15+28= | 400÷5= 14×2= | 200÷5= | 30×9= 60÷3= | 24×3= | 79-16= 45×2= | 12×5= | 10×8=
| 0×8+6= | 3×9+6= 3×8+3= | 9×6+0= | 4×7+2= 2×7+6= | 4×9+6= | 5×8+4= 5×9+5= | 6+8×8= | 3×7+6=
| 405÷5= 2100÷7= | 102×4= 350-80= | 280+90= 2×7+8= | 15×6÷3= 860÷2= | 43×2=
| 84÷4= | 103×2= | 560÷7= 16×3= | 40×30= | 300÷6= | 88÷4= (26+74)÷5= | (35-35)×35= | 83÷83×83= | 760-660÷6=
| 125+396= 304-178= | 1000-304=
| (2)64×2= | (3)375+210= (4)2700÷3= | (5)800÷8= | (6)100-47= (7)2.4+1.6= | (8)2.5+3.6= | (9)544÷9≈ (10)3-0.9= | (11)1.1-0.9= | (12)69×3≈
|