【答案】:
$? =\frac 14×\frac {11}{12}+\frac 1{12}×\frac 14?$
$? =\frac 14×(\frac {11}{12}+\frac 1{12})?$
$? =\frac 14?$
$? =\frac 7{24}+9×\frac 38+\frac 58?$
$? =\frac 7{24}+(\frac {27}8+\frac 58)?$
$? =\frac 7{24}+4?$
$? =4\frac 7{24}?$
【解析】:
$\frac{1}{4} × \frac{11}{12} + \frac{1}{12} ÷ 4$
$=\frac{1}{4} × \frac{11}{12} + \frac{1}{12} × \frac{1}{4}$
$=\frac{1}{4}×(\frac{11}{12}+\frac{1}{12})$
$=\frac{1}{4}×1$
$=\frac{1}{4}$
$\frac{7}{24} + 9 ÷ \frac{8}{3} + \frac{5}{8}$
$=\frac{7}{24} + 9 × \frac{3}{8} + \frac{5}{8}$
$=\frac{7}{24} + \frac{27}{8} + \frac{5}{8}$
$=\frac{7}{24} + (\frac{27}{8} + \frac{5}{8})$
$=\frac{7}{24} + 4$
$=4\frac{7}{24}$