58+42= 66+52= 49÷7= 16×6=
280-145= 140+126= 63×3= 76+24=
96-31= 128×4= + = 1- =
74+36= 58+36= 96-64= 27×4=
77-25= 29×3= 23×5= 76+39=
- = - = 1- = 1- =
670-41= 425+25= 4×209= 17×8=
909×0= 8×500= 350+15= 650-180=
+ = + = - = 1- =
682-78≈ 304×3≈ 27-7×2= 32+0÷8=
800×6= 15×30= 84÷4= + =
- = 210÷7= 16×40= 1- =
5-1.03= 0.08+8.8= 3.78+7.22= 10-5.8+4.2= 91÷13=
23×6= 287÷40= 35÷5×2= +
700×6= 32×3= 56÷7= 34+8= 308+107=
+ = - = 1- = + = 312×2=
40+400= 600×5= 48÷4= 90÷3=
360÷9= 12×8= 70-49= 65÷5=
69×0= 7×80= + = - =
① + ② + ③ + ④ -
680-40= 270÷ 9= 54÷6= 0×1000=
130+570= 400×2= 1- = =
402×5≈ 601-398≈ 68×9≈
125×8= 609÷3= 100-19= 12×50=
17+83= + = 1- = 1平方米-1平方分米=