jmc

The number of cans in each row form an arithmetic sequence, with first term 1 and common difference 2. If there are $n$ terms, then the terms are 1, 3, $\dots$, $2n-1$.

The total number of cans is therefore the sum of the arithmetic series $$1+3+5+\cdots +(2n-1).$$The sum of an arithmetic series is equal to the average of the first and last term, multiplied by the number of terms, so the sum is $[1+(2n-1)]/2\cdot n=n^2$.

Then from $n^2=100$, we get $n=\boxed{10}$.