*How to get 7.04 points per dollar buying fireworks on July 4th (7/04). *

Happy Fourth of July! Today’s post is a silly challenge: how to buy fireworks on July 4th (7/04) and earn 7.04 points per dollar. This is similar to the Pi day challenge I did in March (see “Pie at 3.14X for Pi day 3/14”), but with an added twist: today we want to use a Chase *Freedom* card to make the purchase.

On Pi day, I took advantage of the Sapphire Preferred card’s 7% annual dividend to come up with a way to buy a Pie kit for 3.14X. With the Freedom card, things are a bit more complicated because the Freedom’s reward structure is more complicated….

The Freedom card has two great benefits that I’ll take advantage of here (besides its name). The first is that the card offers rotating 5X categories each quarter. This quarter the categories are restaurants and gas stations. Most gas stations carry firecrackers and the like, so we’ll buy our fireworks there. The second benefit the card offers is dependent upon having a Chase checking account. Once you have both the Freedom card and a checking account, you qualify for the Chase Exclusives program. With Chase Exclusives, your base rate increases from 1 to 1.1 points per dollar AND you get a fixed 10 points per transaction. Within a 5X bonus category you would earn 5.1 points per dollar plus 10 points.

### Algebra

I had to send my brain back to 8th grade algebra to figure this one out:

Given, F = price of fireworks (after tax), our goal is to earn 7.04 points per dollar. In other words, we want to earn 7.04 x F points. Our formula then is:

7.04 x F = F x 5.1 + 10, therefore:

7.04 x F – F x 5.1 = 10, therefore:

1.94 x F = 10, therefore:

F = 5.154639

In other words, if we spend $5.154639 to buy fireworks at a gas station, we would earn 7.04 points per dollar. Unfortunately, most gas stations do not take denominations smaller than a penny, so we need to round down the amount. When we round down to a payment of $5.15, we see that we earn 36.265 points. Unfortunately, Chase is likely to round this down to 36 points which completely messes up the math. After playing with some amounts *and *accounting for rounding, I found that a payment of $5.11 results in 36 points which comes to 7.045 points per dollar. Sure, technically this is closer to 7.05X, but I’ll take it.

### Buy fireworks for 7.04X

So, there you go. Simply get a Freedom card and a Chase checking account and register for this quarter’s 5X bonus categories. Then, go to a gas station that sells fireworks and find some in which the after tax price will come to $5.11. Easy as pie!

### A word to my son

See! I told you that algebra comes in handy in the real world! And to think that you doubted me…

You’re too funny. Thanks for the entertaining post. Happy 4th to you and yours!

“A word to my son

See! I told you that algebra comes in handy in the real world! And to think that you doubted me…”

This post has nothing to do with real world 🙂

Nice post with the nice complexity we love from FM

Beautiful! Nice to see real world applications! Now, if only the high school textbooks would follow your example: “If Johnny had to get 7.04 poitns per dollar spent, how many firecrackers could he buy, and how many fingers would he have left over?” 🙂 Funny!