Jobs requiring no math knowledge are very rare. If a wage is earned then the employee may want to check the amount paid, the level of tax deducted or verify any overtime calculation. All these aspects require a basic level of math. If money is paid out for goods or expenses then the correct amount given and received in change has to be calculated.
In olden times some land workers lived in rent free houses and instead of receiving wages in money, received it in kind - potatoes, meat, flour etc. Even with this kind of existence a value of the goods had to be established so that the worker and his family could trade their goods for other items that were needed.
Chat with our AI personalities