There are 1000ml in 1 litres. So you need to divide 3250 by 1000. You can use a place value chart to help convert 3250ml to litres. The digits move 3 place value columns to the the right.

The place value chart shows the number 6396. There are 6 thousands, 3 hundreds, 9 tens and 6 ones. To divide this by 3, look at the values in the individual columns. 6 thousands divided by 3 is 2 ...