| 脱式计算. 6450-2600÷650×278 (512+2688÷56)×73 (9640-5230)÷(38+25) |
| (1)6450-2600÷650×278 =6450-[4×(300-22)], =6450-[4×300-4×22], =6450-[1200-88], =6450-1112, =5338; (2)(512+2688÷56)×73 =(512+48)×73, =560×(70+3), =560×70+560×3, =39200+1680, =40880; (3)(9640-5230)÷(38+25) =4410÷63, =70. |
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