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.
Tag: numbersense
Triangular Numbers
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 they form a very interesting pattern when graphed.
Can you guess the next triangular number? Can you guess the shape of the graph of the triangular numbers? Can you explain that graph?
Odd Times
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 classrooms, yet it is an important and a very interesting question. We ask students to explore it, learning to Show and Hide rows and columns in their spreadsheet at the same time. Here again is an interesting pattern in mathematics, one we do not generally expect. Odds and evens often seem to students to be an unimportant distinction, but it is not. Odd and even numbers appear again and again across all of mathematics and in many of our Labs. It is important not only as a pattern, but it tells us to pay attention to odd number products because they are rarer than even number products.
More Number Lines
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 generate and experiment with negative numbers by subtracting below 0. As you build numberlines on spreadsheets you are building them in your mind. And by thinking of numberlines in terms of rules you are getting ready for algebra.
Lights Out
This is one of those math puzzles that come up in contests but which turn out to be quite interesting mathematically. Imagine a long hallway with lights in the ceiling, all on and each controlled by its own chain. A long line of people (as many as there are lights) walk down the hallway. The first one pulls every chain, the second one every other chain, the 3rd pulls every 3rd chain and so on. When all the people have walked down the hallway, what lights, if any, will still be lit? What more can you learn from this puzzle about multiplication?