估算．59+52≈ 66+32≈ 48+76≈ 86+39≈809﹣514≈ 326﹣374≈ 568﹣129≈ 718﹣491≈
计算 21÷121÷．
直接写得数×0.25=÷= 2×÷= 6.3×=÷= 2﹣﹣= 2.6×11﹣2.6= 1.8×4×0.5=
口算我最棒!=========
口算×=×= 12×=+3=÷=÷4=×= 5÷=
直接写得数======
121÷
．
×0.25=
÷
= 2×
÷
=
÷
= 2﹣
﹣
= 2.6×11﹣2.6= 1.8×4×0.5=
=
=
=
=
=
=
=
=
=
×
×
= 12×
=
+3=
÷
=
÷4=
×
= 5÷
=
=
=
=
=
=
=
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