Just plain mental

I've been practicing mental calculations. There are six events at the MCWC - adding ten ten-digit numbers, multiplying two eight-digit numbers, finding the square root (to eight significant figures) of a six-digit number, and naming the day of the week for a given date, plus two "surprise" tasks. In each case you get a certain amount of time to do as many of the tasks as possible - ten minutes for the addition, fifteen minutes for the multiplication and roots, and just a minute for the calendar calculations. Which is a bit of a rush if like me you're not particularly brilliant.

You're given ten of each task, and I can just about do eight additions in the time, and six multiplications. The trick is to keep practicing so that I get most or all of them correct, because I have too many little errors at the moment. Dates is more a case of getting my mind in gear as quickly as possible - once you get going, it really is easy to rattle them off in a few seconds, but I seem to struggle to get warmed up properly.

Square roots are my weak point at the moment. I'm still not entirely sure what approach to take for them. I'd quite like to memorise all the six-digit squares and their roots, which would give me a head start, but it's quite a big task and I worry that that amount of long-term memory stuff would get in the way of the short-term memory stuff I'll want to do for the memory competition on the Sunday.

I've been doing a bit of practice for that, too - did 780 in five-minute binary today, which would equal my world record, but I know I can do more than that on a good day. Also a fifteen-minute number, where I was going for four journeys' worth of digits, 936, but had lots of gaps. I'm pretty sure that's a realistically possible figure, though, so I'm going to stick with it. I'm just pleased that I've been more or less in the training mood today!