Third graders (and students in other grades as well) are often asked to identify patterns in a series of numbers. For example, given the following series of numbers: 7, 10, 13, 16, students might be asked to identify the next two numbers in the series or describe what mathematical “rule” is creating the pattern (in this case, the rule is “adding 3”). So I figured this was a perfect opportunity to teach the students in Ms. Boone’s class at Chamberlayne Elementary about spreadsheets and formulas. I gave them a Numbers template that you can download by clicking here (I just adjusted the size of the cells and fonts). I told them to enter any 2-digit number into cell B2. Then in cell C2 we wrote a formula “=B2 + 3” and pressed the Enter key. The answer automatically appeared in the cell. Then I showed them how they could click in the cell and drag the little dot in the lower right corner to fill in the neighboring cells and create a pattern. Next they wrote the rule in the box. We continued in a similar manner writing formulas for subtraction, multiplication (use *), and division (use /). Once the students understood how to write formulas, I let them write a formula of their own. Then a partner had to enter a number and see what the “secret” formula did to that number. Their goal was to try to identify the formula or rule that was creating the pattern. Some students discovered that certain numbers (like 0 or 1) were very helpful in figuring it out!

Third graders in Mr. Friend’s class are studying fractions, so today I showed them how to make fraction pies using a program called Numbers (the Mac version of Excel). The was the first time many of them had seen a spreadsheet so I explained the parts. The naming of each cell, (A2, B4, etc) was familiar to them because they studied map grids which use a similar format. I explained that we couldn’t just write a fraction like 3/4 in the cells and generate an accurate fraction pie. To show them what happens we typed 3 in A1 and 4 in A2, highlighted them both, clicked the Charts button and picked a pie chart. It made a fraction pie that looked like 3/7. After trying a couple more that way, the students figured out that the computer is taking the top number and making pieces of pie one color, then taking the bottom number and making pieces of pie another color. So they had to “trick” the computer into making the correct pie chart to represent the fraction accurately. In order to get a pie showing 3/4, we had to type 3 on top and 1 underneath. We tried that strategy with a couple of basic fractions until they got it right. Then they made up their own fraction, created a pie chart for it, and their neighbor had to identify the fraction. Before saving their work, I showed them how they could change the colors of the pies (they love that, but I try to save it until the end or they get distracted by it)! If you’d like to try another Numbers activity comparing fractions and showing mixed fractions, look at this post.