How to compare rewards credit cards with the NPV() function

In this post, we’ll show you how to compare different credit cards that have different sign-up bonuses, annual fees, rewards, etc. We’ll use the NPV function, which allows us to compare different streams of cash flows that come at different times.

A word of caution: Our post assumes that you’ll pay off your credit card in full each month. As we mentioned in our personal finance modeling post, the rate of return earned on investments is one of the key factors in achieving long term financial independence. We assumed getting a 4% return on our investments…the average interest rate you’d have to pay on a credit card balance is 15%! That’s like having a huge negative investment, which could keep you in the poor house. Continue reading “How to compare rewards credit cards with the NPV() function”

Classroom Seating Layout Spreadsheet

What seating arrangement is best for your classroom? Traditional rows and columns? U-shaped? Clusters?  Do you want your students seated alphabetically or randomly? Use this spreadsheet to plan and experiment with various seating layout options for your classroom! Continue reading “Classroom Seating Layout Spreadsheet”

Check the “Rule of 72” with a spreadsheet

One of the more amazing things I’ve encountered while studying finance is the Rule of 72. This rule effectively tells you how long it would take to double your money, depending on what interest rate you are earning on it. So if you were earning 4% a year, it would take roughly (72/4) = 18 years to turn $1,000 into $2,000.

But does it really work? Let’s verify with a spreadsheet! Continue reading “Check the “Rule of 72” with a spreadsheet”

What’s the expected value of your Powerball ticket?

As the Powerball jackpot grows to over $300 million, we start to wonder if maybe buying a ticket is “worth it.” While the lottery is “worth it” in that ticket sales goes to things like state education, buying tickets is typically not worth it for yo because the projected payoff is far less than the ticket price. Continue reading “What’s the expected value of your Powerball ticket?”

How much money do you need to retire?

As mentioned before, we love browsing through the questions and answers on Quora. Every Quora session reveals financial success stories, inside views into jobs and companies, and some practical life advice.

One topic that comes up frequently is how much money one needs to stop working. That is a question that spreadsheets are well-suited to solve! Let’s build our Financial Freedom Spreadsheet Calculator. Continue reading “How much money do you need to retire?”

The “360 spreadsheet” for teachers and educators

We first heard of the 360 spreadsheet from the book Hacking Education: 10 Quick Fixes for Every School by Barnes and Gonzalez. This post* (and more to come) will cover how spreadsheets can be a tool for those with a love of teaching, learning, and inspiring others.

A 360 spreadsheet is a simple tool that provides teachers with a more complete, “360 degree” view of each student. Basically, it allows them to get to know their students on a deeper level, all in one place. We created a slightly enhanced version of the 360 spreadsheet in Google Sheets, which has many benefits. We’ll show you how we added new features to this spreadsheet, which you can download below.  Continue reading “The “360 spreadsheet” for teachers and educators”

Play Jeopardy at home with this Mobile Spreadsheet

This is the third in our three-part series of designing spreadsheets entirely on our mobile devices. Part 1 was a New Year’s resolution keeper and Part 2 was a weighted lottery to make a group decision on where to go for lunch. Today we’ll build a spreadsheet on the iPad that allows you and your friends to play along with the Jeopardy TV show, all while keeping score for a friendly competition.

Continue reading “Play Jeopardy at home with this Mobile Spreadsheet”

Build a weighted lottery spreadsheet to decide on lunch with friends

Taking a walk and grabbing lunch is one of the simple pleasures of the workday. Unless of course, you bring your lunch to work. Sometimes with a group of people it is hard to decide on where everyone should go to lunch together. Maybe only one person enjoys the guilty pleasure of Taco Bell, while the others want to stick with Whole Foods. Or maybe half of the group wants burgers and the other half pizza.

Here’s a relatively simple Google Mobile spreadsheet. It’s part 2 of our mobile phone spreadsheet series (See Part 1 on Tracking New Year’s Resolutions) that uses a weighted lottery to fairly determine where to go for lunch, taking into account each person’s individual preferences. Basically, each person gets 10 “points” to allocate to three restaurant choices. Each point is effectively a lottery ticket, and the spreadsheet randomly chooses the restaurant, with the probability weighted by how many points each restaurant has received. Continue reading “Build a weighted lottery spreadsheet to decide on lunch with friends”

Track New Year’s Resolutions on Mobile Sheets

This is the first in a series of posts focused on the Google Sheets app on our mobile phone, rather than the typical desktop spreadsheets. We use the mobile Google Sheets app to set our New Year’s Resolutions and track what percentage of days we have fulfilled our promises. Hopefully, having this tracker on our phone and nearby at all times makes it slightly easier to fulfill our resolutions! Continue reading “Track New Year’s Resolutions on Mobile Sheets”

Keep New Year’s Resolutions with Spreadsheets

new-year-hatWhat are your new year’s resolutions? As in most cases, coming up with the goals is easy…but achieving them is another story! According to a Forbes article published a couple of years ago, only 8% of Americans achieve their resolutions. How can we keep our resolutions? Can we be better at goal-setting? As an organizational and prioritization tool, spreadsheets can keep us accountable and help us reach our goals. In our busy lives, it can be a challenge to keep track of and prioritize everything we set out to do. Spreadsheets can help by making us better managers of our lives. Continue reading “Keep New Year’s Resolutions with Spreadsheets”

Build a Secret Santa Spreadsheet

Christmas is here again, and while we at SpreadsheetSolving appreciate the festive spirit, our practical side always wonders “does every single friend need a gift from each of their other friends?”. And… “why can’t we just give cash?”

The game Secret Santa somewhat lessens this gift giving burden among a large group of people. In this game, each person is secretly assigned one other person in the group to give a gift to. Typically, when the person opens their gift, they try to guess who gave it to them. Great fun is had by all (in theory).

We can create a simple spreadsheet to set up the random assignment of people to others in a group. First we enter in a hypothetical list of names: Continue reading “Build a Secret Santa Spreadsheet”

Will you pay more or less under the Trump Tax Plan?

After nearly a year and a half after the candidates first declared their intention to run for the Presidency, we have now elected a new President. Trump’s Presidency was a surprise to many, and with Republicans in control of both the House and Senate along with the Presidency, major changes could be possible.

One of those changes could be taxes, where Trump has proposed a tax system with three tax brackets of 12%, 25% and 33% and an increase in the standard deduction to $30k for joint filers, while also eliminating exemptions for dependents. We wondered: roughly how would taxes change for any given level of income, filling status, and number of family members? This is a problem spreadsheets are well suited to solve! Continue reading “Will you pay more or less under the Trump Tax Plan?”