So ds has been given a table with loads of data. All the numbers are over 10,000. There are 8 questions on the data. Each question requires him to add a column of about 10 numbers e.g. 12,242 + 19,111+ 20,342 + 42,342 etc ( you get the gist).
Now he decided to add the first two together and go on from there e.g. 12,242 + 19,111 = 31,353 + 20, 342 = etc..... Then with prompting from me he added the first 5 together and then the next 5 and then added the two answers. Either way it amounts to alot of addition (and a lot of time) and I can't help thinking there must be a method he may have missed when off sick or something. This is year 6 maths. I have spent time googling but maths is not my strong point and frankly I am baffled. Help appreciated.