One boast you'll never hear from me is that I have a good head for numbers. I'm all right up to two figures beyond a decimal point — I know that 3.14 approximates to the 円周率 (enshūritsu, Pi, i.e., the ratio of a circle's circumference to its diameter) and likewise 2.54 cm is approximately one inch. But for just about anything else I have to reach for my trusty 電卓 (dentaku, electric calculator).
But thanks to the Japanese system of mnemonics called 語呂合わせ (goro-awase), I can perform tricks that might fool you into thinking I'm some sort of numbers wizard.
For instance, I can unfailingly recall my telephone number from 38 years ago.