（2023 四下.上海月考）递等式计算, 能巧算的要巧算。

(1) $7.49+4.51-6.479$ (2) $6.35+8.24+1.65+2.74$ (3) $374 \times 83-83+83 \times 27$

(4) $11000 \div 125$ (5) $31 \times(21-65 \div 5) \times 25$ (6) $6000 \div(125 \times 6)$
解: (1) $7.49+4.51-6.479$

$=12-6.479$

$=5.521$

(2) $6.35+8.24+1.65+2.74$

$$
\begin{aligned}
& =6.35+1.65+(8.24+2.74) \\
& =8+10.98 \\
& =18.98
\end{aligned}
$$

(3) $374 \times 83-83+83 \times 27$

$$
\begin{aligned}
& =83 \times(374-1+27) \\
& =83 \times 400 \\
& =33200 \\
& \text { (4) } 11000 \div 125 \\
& =(11000 \times 8) \div(125 \times 8) \\
& =88000 \div 1000 \\
& =88
\end{aligned}
$$

(5) $31 \times(21-65 \div 5) \times 25$

$=31 \times(21-13) \times 25$

$=31 \times 8 \times 25$

$=31 \times 200$

$=6200$

(6) $6000 \div(125 \times 6)$

$=6000 \div 6 \div 125$

$=1000 \div 125$

$=8$