Answer: The required number is 400.
Step-by-step explanation: We are given to find the number such that 4,000 is ten times as much as that number.
Let x represents the required number.
Then, according to the given information, we have
[tex]4000=10\times x\\\\\Rightarrow 4000=10x\\\\\Rightarrow x=\dfrac{4000}{10}\\\\\Rightarrow x=400.[/tex]
Thus, the required number is 400.