Check what number is in that place and check to the one to the right to see if it greater than five, if so round up 1
Like in this case, 3 in 5370288 is in the 100000 place, the one next to it is a seven which is greater than five so you add 1+3 to get four and replace the three with a four and make all the numbers next to it in the right a 0 aka 5400000