The main thought is that Harold should round off all his data to the nearest hundredths place so that all would have 2 decimal places. The most efficient way would be to use software tools like MS Excel. This is very useful especially in collating and analyzing data because it has different features like inputting formula to the cells, data fitting, different types of graph, iteration, and linear regression.
For reducing all decimal places to 2 numbers only, highlight all of the data, then place your cursor as shown in the picture encircle in red. This feature automatically rounds off your data in one click per decimal place. I've given examples of lengthy numbers shown in the left side. Just click the 'decrease decimal' button until it reaches to just two numbers, as shown on the right side. Using this MS Excel feature, it will save time for Harold.
