Why is this not correct way of calculating real value ( stupid question)?

Question

• inflation $= 3\%$ per year,

• amount of time $= 5$ years,

• nominal value = $\$5070.6$,

• real value = ?

• real value* $1.03^5 = \$5070.6 $, real value = 4373.94, this is correct answer

• why not : $5070.6\times(1-0.3)^5 =$ real value, which gives answer $\$4354.3$ for real value