I saw an example of this on Griff Rhys Jones’s “Greatest Cities of the World” when he was in Hong Kong. Primary school kids were adding and subtracting strings of three figure numbers almost instantaneously in their heads while Griff was failing to keep up using a calculator.
I like the idea of possessing this skill but I’ve never used an abacus nor do I have any idea how difficult it would be to develop a mental abacus, but if eight-year-olds can do it, I’m guessing it’s achievable for the average adult with enough time on their hands.
Does anyone here have any experience with this? How hard is it to become proficient enough with an abacus that you no longer need a physical abacus any more? Are there differnt types of abacuses that are more or less suitable to this?
Er, if it’s in your head, why does it have to be based on the mechanics of an abacus? Would you be open to any other method of carrying out mental arithmetic?
Thing is, all an abacus does, essentially, is keep track of beads in a ones column, a tens column, a hundreds column, and so on, and you go through the columns adding/subtracting and carrying/borrowing in essentially the same way as you would probably already do arithmetic on paper or in your head anyway. If you have better visual memory than, uh, digit-string memory, then imagining the abacus could perhaps be helpful for keeping track of what’s going on, but I can’t see how it would make anything any faster.
So I’m afraid I don’t know what it is about the abacus method of mental arithmetic which makes it supposedly so fast, beyond, I imagine, practice. But you can practice anything, and you already presumably have a hell of a head start practicing however you currently do mental arithmetic.
The rods on my mental abacus are very loose. Any time I try and add more than a couple digits together, they slip out and beads fall all over the place. Horrible. It’s fairly crippling, in that I can do some fairly complex math on paper but am utterly lost when it comes to mental math agility.
Right, but the kids in this show were doing it instantaneously. The teacher was rapidly reading out a list of numbers, each being subtracted or added to the last, and the moment he stopped, they all put their hands up with, presumably, the correct answer (at least, whoever he asked had the correct answer). I found it pretty impressive, especially in kids that young.
There are a number of methods of mental calculation:
It’s not clear that the chisanbop method is any better than a number of others. Also, it’s not necessary to learn how to use an abacus (or even to have ever even seen an abacus) to lean chisanbop. Being good at mental calculation is a matter of learning a mental technique (or inventing it yourself). This takes some significant amount of time. Given the existence of calculators these days, why bother?