Tag: addition and subtraction

Make a Hundreds Table

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 the fewest steps. There are many ways of doing this and students can be as creative and exploratory as they want. Nor should they feel limited to tables that start at 1 and go to 100. These rules, these patterns should enable them to start anywhere and build any size table they can imagine. We strongly encourage students to stretch their minds here and to think outside of this box.

Addressing

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 bars, but all use the same format, letters for columns and numbers for rows with letters first and numbers second. We introduce this on the hundreds table which could be thought of as a miniature spreadsheet and use number lines to provide some additional feedback. Using addressing enables us to build rules as patterns and to put anything we want into cells to use those rules on. It is the great power of spreadsheets.

Number Lines

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 to build a variety of number lines using rules. For example they can build a whole number line by creating a rule that adds 1 to the number in the previous cell (=J9+1) and then copy that rule across the numberline cells. They build numberlines with only odd numbers, even numbers, and starting with different numbers. We encourage them to explore a variety of rules to make different numberlines.

Fibonacci’s Sequence

Fibonacci, the nickname given the great medieval mathematician Leonardo of Pisa, is connected in most of our minds with the Fibonacci sequence. Spreadsheets make wonderful tools for creating such sequences. This one is amazingly simple. Just select a cell, any cell and write a formula in that cell that adds together the two cells above it. Now copy that cell down the spreadsheet and seed it with 1 in the first cell. The Fibonacci sequence is a pattern that this action shows very well. This sequence has surprising attributes, and we explore some of them as well.

Sudoku Challenge

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 that all of the numbers appear only once in every row, column, and grid square. Ryan added a sweet wrinkle to the traditional Sudoku game, he gives you the sums so that you not only get to practice addition, you can get some hints about the numbers you should input. Can you use our template to create your own Sudoku challenge?