# Making Fractions

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 it seemed only right to use the power of spreadsheets to help students and teachers to gain some fraction-sense. This is a very simple spreadsheet that uses histograms to compare fractions. We expect students to play with this and to put in different fractions and guess which ones will be bigger or smaller and then check their guesses. This Lab only works on Excel Spreadsheets because they are the only ones we know of that display fractions in their native form.

Open in

Open in

# Place Value: Decimals

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.

Open in

Open in

# Common Denominators

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 denominator of 2/3 and 3/4 is 12. We then can use the common denominator to add/subtract and divide common ratios (fractions). This approach to division is quite different from the traditional approach and does not rely on the mechanical process of inverting the divisor and multiplying which most students find difficult to understand. Using common denominators means that to divide two fractions we simply divide the numerators of their common denominators, because when we divide common denominators they =1 since both have the same value.

Open in

Open in