Greetings everyone,

I got a letter from my credit union about an easy start 1 year certificate with an APY 4.85% . It's where u can open one for $100 and make $25 monthly payment towards it and after a year when it matures the total will be $411.

I was trying to find out how they come up with $411.
25*12=300 and 100 to begin with so thats $400. Can someone please tell me how they got the additional $11, thank you.

That $11 is your accrued interest. Figure ~5% on the first $100= $5 by years end. The other $6 is from compounding as you deposit additional funds.

Anyway, that's roughly what it is without punching in the numbers to get the exact compounding figures.