When an Australian mom posted a TikTok video on how to save $5,000 in just 25 weeks, her hard-to-believe financial hack went viral. Now, the “Money Challenge” is inspiring people to up their savings game. In the widely circulated video, Becky Turiczi unpacks a tutorial on how she achieves her savings goals with only a tin can, a piece of paper, stickers, a marker, and sticky tape. Her method employs a clever strategy. On the sheet of paper, Becky writes numbers from 1 to 100, then tapes the paper to the tin can. Then, over the course of 25 weeks, she deposits amounts between $1 and $100, crossing out the corresponding number on the piece of paper by placing a star sticker over it. Anyone who does this through to the end of 25 weeks, crossing out every number, will end up with $5,050 inside the tin can. Simple. You can …