口算。3-= -= 6÷= (+)×21313×89= 0.9×99+0.9= 1-+=2.3+ 3.57= 0.5×(2.6-2.4)= 0.25×4÷0.25×4=
10×1=____ 10×2=____ 10×3=____ 10×4=____
41+7= 43+4= 47+7= 48+8= 81+7= 83+4= 87+7= 88+8=
76+5= 78+3= 72+9= 77+7=
63+9= 65+7= 64+8= 67+9=
52+7= 56+7= 58+4= 59+6=
= 
-
= 6÷
= (
+
)×21
+
== -= 6÷= (+)×21+=
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