What is the Train Game?

Combine four numbers to equal 10 using only +, −, ×, ÷ and brackets.

The Train Game is a rite of passage for Sydney-siders. Upon stepping onto a train carriage, a group of friends will immediately turn to the carriage number—a four digit number—and race to find a way to make it equal 10.

Inevitably, someone will use an invalid operator like "the power of" and an argument will ensue. It makes for an entertaining way to pass the time.

In this solver, the four numbers must be solved in order (left to right), though brackets can manipulate the order of operations.

Note: Not all combinations have a valid solution.