0.1 + 0.2 equals apocalypse: how floating-point glitches doomed missile defenses, stock indexes, and your startup's budget

A fundamental issue in computer programming has been causing significant problems in various industries, including finance, science, and technology. The problem arises from the way computers store decimal numbers, which can lead to small errors in calculations. For example, the equation 0.1 + 0.2 does not equal 0.3 in most programming languages, including Python, JavaScript, and Java. This issue has caused multi-million dollar disasters, such as the failure of a Patriot missile defense system in 1991, which resulted in the deaths of 28 soldiers. To address this problem, developers can use techniques such as epsilon comparisons, integer arithmetic, and decimal libraries. The Python decimal library, for instance, can be used to perform exact decimal arithmetic. By understanding the limitations of floating-point arithmetic and using the right tools, developers can write more resilient code and avoid costly errors. This issue affects many industries, including finance, where small errors can add up quickly.