What can be created using exactly four 1s?

At first, the challenge seems to be simple.

Think about representing numbers 1, 2, 3, 4...Then, suddenly, a thought arises: "How can we represent numbers like 37, or 42, or 49 using just... four 1s?"

As the numbers grow bigger, new symbols arrive: Factorials join the game, square roots begin to multiply.

And then... the puzzle transforms into a mathematical journey.

In this volume, the numbers 1 through 50 are constructed using exactly four 1s. Some are straightforward, some unusual, and some are delightfully absurd..