cincuenta
/θinˈkwenta/ · B1 · num
fifty
🖐️ cinco (five) + -uenta (tens) = five tens = fifty
It comes from Latin quinquaginta, built on quinque, meaning five. The same -enta ending marks the other tens too: cuarenta is 40 and sesenta is 60. Once you know cinco, the cin- at the start of cincuenta tells you it means fifty.