If you are a high school student or graduate student interested in joining the US military, you will need to take the military version of the entrance exam first. Armed Forces Professional Skills Battery, also known as ASVAB. This exam tests your math skills, among others. No one is allowed to use a calculator.
Many prospective recruits are excluded from this concept. In today's modern-day, when everything is a smartphone or computer app and clickable, the idea of math without a calculator may seem implausible. To learn short tricks to solve math problems, you can take an online ASVAB course at https://www.andysasvabclass.com/ for best practices.
It's a brilliant move for military examiners. They don't see if they can recreate the information you learned in high school and maybe college. Instead, they try to test your understanding, knowledge, and conclusions so far.
In the military, they don't care if you can press a few buttons to get an answer. Instead, they want to see if you can think of a potentially simple problem and even some difficult ones.
Because of this, they don't give you complex math problems that can be solved at the push of a button, but rather a combination of simple and complex math problems where you have to think about and develop strategies to solve each concept.
If you are a dedicated student who is motivated to pursue your military career dreams, you will likely be prepared for questions that do not exist on the ASVAB calculator.