I redeemed a series ee paper savings bond. The amount on the bond was $100 but I got about $140 when I redeemed. The bank didn't give me anything in terms of breakdown on interest. Is the interest $40, $140-$100 face value paid?
No. Not the Redeemed amount - Face value. You probably paid less than the face value when you bought it. Like only 50%. You have to find what you bought it for. Anything over your cost is the interest.