This video will show you a quick method of rounding a number to 4 decimal places (4dp). To round the number off to 4 decimal places, put a line in after the first 4 digits after the decimal point. If the number after the line is less than 5, round the number down (keep it the same). If the number is 5 or above round the number upwards. So in example 1 you need to round 4.17356 to 4 decimal places. This means you have two choices, either 4.17356 or 4.17357.