Question

Using the divisibility test, determine $21084$ is divisible by $4$, by $8$ or not?

Answer 1

Step $1:$ Explaining the divisibility test:

Divisibility test of $4$: A number is divisible by $4$, when the last two digits of the number is divisible by $4$

Divisibility test of $8$: A number is divisible by $8$, when the last three digits of the number is divisible by $8$

Step $2$: Finding whether $21084$ is divisible by $4$, by $8$ or not

The given number is $21084$

Last two digits in $21084$ is $84$

Clearly, $84$$÷4=$$21$

Thus, $84$ is divisible by $4$, therefore $21084$ is divisible by $4$

Last three digits in $21084$ is $084$

Clearly, $084$$÷8=$$10.5$

Thus, $084$ is not divisible by $8$,therefore $21084$ is not divisible by $8$

Hence, $21084$ is divisible by $4$ but not by $8$