The absolute value (ABS) function is the positive value of a number or quantity. Its graph has a very peculiar shape, a V. Since absolute… Continue

What would you guess the absolute value of a polynomial function would look like? Try some here. I think you will be very surprised. Can… Continue

Adding to 10 is but on example of a large number of spreadsheets that could be developed to practice addition. We give students two number… Continue

Now that students can build addition tables, they should look for the patterns in them. We introduce them to a variety of things they might… Continue

From here on students can go in most any order they choose. They can start with addition or with multiplication. They should imagine themselves on… Continue

We have been using cell addresses informally until now, but now we can be more formal and explicit. Different spreadsheets have different types of address… Continue

Parentheses are not only important in paper math, they are critical in spreadsheets. To make sure that terms are handled properly by spreadsheets, we have… Continue

Spreadsheets can be a great place for you to build your own games. Ryan has built one of his early favorites, Battleship, where you learn… Continue

In a class of 23 students, the chances are fifty-fifty that two of them will have the same birthday. Now that may sound impossible since… Continue

Students are tasked to build a times table in just two steps. They have to learn to use absolute as well as relative addressing to… Continue

Spreadsheets offer us a nearly unlimited ability to develop and learn from case studies using real world data. We will focus mainly on climate change… Continue

Are you a coffee drinker? Small daily expenses like coffee can quickly add up. By using spreadsheets to organize cost, you can monitor how much… Continue

We can use these proportions to compare two ratios with different denominators by finding a denominator that their proportions have in common. Thus the common… Continue

The symmetry of the multiplication table around the square numbers diagonal we call commutativity or the commutative property. It means that in a 12 by… Continue

One of the most powerful aspects of the mathematics of functions is our ability to treat them as abstract quantities (essentially numbers) and then combine… Continue

How much are your credit cards costing you? If you are like most of us, they are very expensive because we have credit card debt.… Continue

Decimal addition is one of a series of Labs to help you understand and learn to use decimals. I think you will find it fun… Continue

Decimal Division is one of a series of Labs to help you understand and learn to use decimals. I think you will find it fun… Continue

Decimal subtraction is one of a series of Labs to help you understand and learn to use decimals. I think you will find it fun… Continue

Ratios can be written in a wide variety of different way: as fractions, as decimals, and as percents.,with a colon, with a slash, as a… Continue

The distributive property turns out to be central to a surprising variety of important mathematics. One of the most valuable is to use it to… Continue

Though spreadsheets lets you put geometric shapes on the screen, those shapes are not connected with the cells and cannot be changed by using different… Continue

Spreadsheets are great for creating secret codes and for breaking them. During World War II the German military used a machine they called Enigma to… Continue

Fractions are ratios that’s why we call them rational numbers (ratio numbers). If you think about fractions as ratios, how does this help you to… Continue

What if you created a function where the exponent is a variable? As you might expect, this would be called an exponential function. When you… Continue

Multiplying creates products, factoring separates a product into the numbers that make it up. We thus start with the table and then look at the… Continue

Spreadsheets always automatically perform the operations you ask them to do. But sometimes we want to see the process. We can make spreadsheets show us… Continue

If you commute to work or school, you understand how expensive driving can be. Choose a car in this interactive spreadsheet as it breaks down… Continue

The GDP or Gross Domestic Product of a country is one measure of its wealth. What can this data tell us about the U.S. economy?… Continue

Graphs as we know them were first invented by Galileo. They are powerful images of functions. I will introduce you to graphs by letting you… Continue

In 1941, Joe DiMaggio got a hit in 56 straight games. This record has never been beaten. Some say it is the greatest record in… Continue

How many of the numbers from 1 to 100 are in the times table? All, Most, Less than half? I think you will find in… Continue

We introduce students to more complex patterns and rules in hundreds tables. In particular, we have students look at diagonal patterns and develop rules to… Continue

In introducing Spreadsheets we want you to learn to build a numberline by using a rule (a formula). We begin with a simple rule that you can copy… Continue

What if you built a rule that would enable you to count backwards? How would it be the opposite of addition? What would happen if… Continue

Spreadsheets make it very easy to switch axes and add graphs. They enable students to play with what may have been difficult and abstract concepts… Continue

The variables in most of the functions we are used to working with vary directly, as one goes up the other goes up. What do… Continue

If you are in the market for a new car, you often have a decision to make. Do you want to buy the car or… Continue

Manage a business. The Lemonade Stand has been a business simulation developed in many different versions. We believe this is the first time that it has… Continue

Linear functions are the most important family of functions. They pervade our everyday lives and our work. Their graph is a line, and their general… Continue

We often see Lissajous figures in old sci-fi movies because they are so cool. As you play with them I think you will find them… Continue

What if you made a series of unit fractions with the odd numbers as their denominator, added the first two together, subtracted the next one,… Continue

This is the graduation exercise for the basic use of spreadsheets. We combine rules and addressing to have students build their own hundreds table in… Continue

Spreadsheet math generally focuses on ratio and proportion to develop the concept of fraction. But fractions is such a big problem in today’s curriculum that… Continue

How should you figure out your profit? If you have an item that you are selling, should you price it at 25% over its cost… Continue

It was one of the most amazing visions of the future ever made. In 1965 Gordon Moore, one of the founders of Intel, proposed a… Continue

We use rules to build new numberlines. For example we can start in the middle and go both forward or backward using adding and subtracting rules. You can even… Continue

George is in New York and Martha is in Washington. They leave at the same time and follow the same road to meet each other… Continue

When Napoleon conquered Egypt in 1798 he went to the Great Pyramid of Giza. While his men climbed to its peak, he figured out that… Continue

Most museums with math exhibits have a Pascal’s triangle made up of pegs with balls falling down between them and bouncing off of them. One… Continue

Number Lines introduce students to functional thinking and the use of formulas in spreadsheets. For younger students we call these formulas “rules” and ask students… Continue

Spreadsheets make it easy for us to explore patterns in the whole numbers. This Lab does that and helps you learn the basics of spreadsheets… Continue

How many of the products in a 12 by 12 times table are odd numbers? This is a question we rarely ask in paper-based math… Continue

Parametric equations are powerful tools to model projectile motions and to graph things that are not functions like circle or ellipses. The x and y… Continue

Another famous pattern, Pascal’s triangle, is easy to construct and explore on spreadsheets. Create a formula for any cell that adds the two cells in… Continue

Pennies to Heaven is a Fermi Problem, basically a “headmath” experiment. Fermi Problems, originally developed by Enrico Fermi, one of the greatest experimental and theoretical… Continue

How much money do you spend? How much money can you save? We all need to know these things, but you can’t know them until… Continue

Use spreadsheets to compare popular phone carriers and the plans they offer. Continue

Our number system inherited from India and from the Medieval Arab world enables us to use just 10 symbols to write any number we can… Continue

We take our place value generator to decimals to help students see the simplicity of the place value pattern going right as well as left. Continue

Polynomial functions are not limited to the highest term and while that term is most important in determining the shape of its graph, additional terms… Continue

Adding an exponent, sometimes referred to as a ‘power’, to the input variable of a linear function that passes through the origin creates a power… Continue

You just won the Lottery worth $600,000,000. You have a choice between taking it as a lump sum of $376.9 million or in yearly payments… Continue

The prime numbers are among the most fascinating objects in all of mathematics. While we can generate them, we do not know or understand their… Continue

That probability is multiplicative is not an easy concept for many of us. Using the spreadsheet with our ability to make tables and to cut… Continue

Using the times table, students can see that products are always rectangles, and that they represent the area of that rectangle. They should explore the… Continue

What does each of the coefficients do? How does it change the graph of the parabola. What does a do, what does c do and… Continue

We look at world population over the past 60+ years and ask whether the earth’s population is growing faster or slower today. Is it out… Continue

We think about ratio tables in terms of motion. Move up 2 and over 1, or move up 1 and over 2. In this way… Continue

The rule of 72 is an old banker’s rule of thumb to find out how long it will take to double your money at different… Continue

Shapes introduces student to changing the colors in cells and to changing the shapes of cells by dragging the column or row separators in the… Continue

Fractals are a new 21st century mathematics. They are patterns that repeat themselves at various scales. This one is based on the odd numbers in… Continue

Spreadsheets are not limited to algebraic functions, they can also display trigonometric functions. We are modeling the sine function, but you can try any of… Continue

When I was young I loved to play with planetary data, to explore their patterns, to learn more about astronomy, and to deal with large… Continue

Typical algebra courses start with equations and solving equations and then move to graphing and functions. We start with functions and use them to solve… Continue

The square numbers form an interesting pattern on the times (multiplication) table. They run along a diagonal from 1 to the top right of the… Continue

Strings need not begin and end on axes that are at right angles to each other which we call Cartesian. It is quite interesting that… Continue

The usual way to make string diagrams using rubber bands or yarn on a board with nails does not allow much exploration. Mary Boole meant… Continue

Have you ever played Sudoku? It is fun and challenging. You have to find the numbers from 1 to 9 in each cell so that… Continue

I built a Lab for you to play with the Syracuse Problem and to learn to use spreadsheets to play with like problems in fun… Continue

Solving systems of equations sometimes called simultaneous equations with graphs is simply a matter of finding out where they intersect. One of the most valuable… Continue

1, 3, 6, 10… are called the triangular numbers because they can be stacked up to form a triangle. They are very interesting numbers, and… Continue

What is “x”? Or how do we represent variables and functions on spreadsheets? Continue

Suppose Tom can paint the entire fence in twelve hours, and Huck takes eight hours. How long would it take the two of them together… Continue