The Scratch-R is a lottery feature/mini-game available via the Kwik-E-Mart. The regular Scratch-R was introduced to the game on January 30, 2013, and the Golden Scratch-R was released on February 28, 2013 which gave the players chance to win Donuts. Read more about the different types of Scratch-R below:
The Scratch-R is a minigame which was added to The Simpsons: Tapped Out on January 30, 2013 along with the Valentine's Day 2013 Event. Each ticket costs the player $250 and you are guaranteed to make a profit of at least $100 every time you play. You have to wait six hours before you are able to buy a ticket for Money again, or you can pay three Donuts for a ticket instantly.
The Golden Scratch-R is a feature which was added to the game on February 28, 2013. It gives the players a chance to win up to 100 Donuts, and as little as six. Each ticket costs $0.99/ £0.69/€0.89. The odds of wining the jackpot are low, but the odds of getting a more unusual combination are higher than which playing on the regular Scratch-R. As of March 2013, it is the most purchased item in the store, despite being there for the shortest amount of time. This could be due to the fact that twelve Donuts are priced at $1.99/£1.49/€1.79 and buying two Scratch-R's for $1.98/£1.38/€1.78 is guaranteed to give at least twelve Donuts for a lower price. A poll was created on the Official game Forum about how many Donuts people had won for the Golden Scratch-R and there was a surprisingly high amount of people claiming to have won the jackpot of 100 Donuts.
There is a slightly higher chance of getting nine Donuts (33.33%) than getting six Donuts (30.37%), according to this  article.
This article contains information about unreleased content, and may contain spoilers.
(This is unknown only conjectural do not rely on it completely)
The Platinum Scratch-R is another version of the Scratch-R. The icon for the Platinum Scratch-R can be found along with the silver jackpot sticker which lies behind the winning combination. It is very likely that the third Scratch-R game will also be playable from the Kwik-E-Mart.. The Platinum Scratch-R will be payed for alike the Golden Scratch-R - with real life money, but it is currently unknown how much the Platinum Scratch-R will cost. Judging by the prizes, the Platinum Scratch-R is likely to cost more. As of 14 March 2014, The Platinum Scratch-R costs £0.69 GBP, which is $1.16 in US money. It's very likely this is a placeholder price, since you get 10x the donuts.