Do you already know everything about numbers? There are even, odd, and fractional numbers, but how many? And do you always calculate correctly? An annual inflation rate of 3 percent results in a price increase of 60 percent after 20 years, or is it 75 percent? Even your ancestors 10,000 years ago had already learned to think. That's why these entertaining stories deal with fundamental mathematical knowledge: with numbers and quantities, calculations and mathematical symbols, powers and their inverses (logarithms), brackets and roots, interest and percentages, simple equations and their manipulation, and finally with profound questions about the extremes: zero and infinity.