200 x 8 x 5 x 4 x 10 =
The answer, of course, is 320,000
You can multiply the numbers one after another manually,
Or you can do it the easy way, with a calculator,
Or you can do it in your head:
look at the whole thing at once,
and recognize that 5 times 4 is 20,
then times the 10 takes it up to 200
which gives you 200 x 8 x 200.
You square 200 for 40,000,
then that times 8 gives you 320,000.
The hardest part is keeping up with the number of zeros.