Question

Find the cube root of $343000$ by estimation method.

• A. $60$
• B. $70$
• C. $80$
• D. $700$

Answer 1

Answer: (B)

$70$

Step $I$: Form groups of $3$ starting from right most digit of $343000$, i.e. $\overline{343}\overline{000}$.

Then, the two groups are $343$ and $000.$

Here, $343$ has $3$ digit and $000$ has $3$ digit.

Step $II$: Take $000$.

Digit in unit place $=0$.

Therefore, we take one's place of required cube root as $0$.

Step $III$: Now, take the other group $343$.

We know, $7^3=343$.

Therefore, we take $7$ as ten's place.

$\therefore \sqrt[3]{3343000}=70$.

Hence, option $B$ is correct.