Megabytes and kilobytes
How many bytes are there in one megabyte?
$1$ kilobyte is actually not $1000$ bytes, it is $2^{10}$ bytes.
$1$ megabyte is $2^{10}$ kilobytes.
How many bytes are there in $1$ megabyte?
This problem is adapted from the World Mathematics Championships
Answer: $1 048 576$
Using powers
$2^{10}$ kilobytes in $1$ megabyte, and $2^{10}$ bytes in each of those $2^{10}$ kilobytes
So $2^{10}\times2^{10}$ bytes in $1$ megabyte.
$2^{10}\times2^{10}=2^{10+10}=2^{20}=1 048 576$, so there are $1 048 576$ (not $1 000 000$) bytes in a megabyte.
Using normal numbers
$2^{10}=1024$
$1024$ kilobytes in $1$ megabyte, and $1024$ bytes in each of those $1024$ kilobytes
So $1024\times1024$ bytes in $1$ megabyte.
$1024\times1024=1 048 576$, so there are $1 048 576$ (not $1 000 000$) bytes in a megabyte.