How many soap cakes can be placed in a box of size 56 cm × 0.4 m × 0.25 m,

Dimension of a soap cake $=7 \mathrm{~cm} \times 5 \mathrm{~cm} \times 2.5 \mathrm{~cm}$

Its volum $e=$ length $\times$ breadth $\times$ height $=(7 \times 5 \times 2.5) \mathrm{cm}^{3}=87.5 \mathrm{~cm}^{3}$

Also, the dimension of the box that contains the soap cakes is $56 \mathrm{~cm} \times 0.4 \mathrm{~m} \times 0.25 \mathrm{~m}$, i.e., $56 \mathrm{~cm} \times 40 \mathrm{~cm} \times 25 \mathrm{~cm}$$(\because 1 \mathrm{~m}=100 \mathrm{~cm})$.

Volume of the box $=$ length $\times$ breadth $\times$ height $=(56 \times 40 \times 25) \mathrm{cm}^{3}=56000 \mathrm{~cm}^{3}$

$\therefore$ The number of soap cakes that can be placed inside the box $=\frac{\text { volume of the box }}{\text { volume of a soap cake }}=\frac{56000 \mathrm{~cm}^{3}}{87.5 \mathrm{~cm}^{3}}=640$