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 imagine. Students learn in this spreadsheet to enter numbers, to compare compact and expanded forms of those symbols and to add units to any number. Students who like to explore further can extend the place values from 3 digits to more and learn the trick that lets them include any kind of text with numbers they can change.
Category: Numeracy
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?
Hundreds Table Patterns
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 fill them. This spreadsheet hundreds table practice is designed to build numbersense, the primary building block for a strong math education. We encourage students and teachers to develop more spreadsheets like these to exercise and develop numbersense.
Factor Table
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 that in several ways. Here we show the factors and have students build a times table showing the factors by using a special formula called Concatenate which means join together. This enables us to create a table of factors that we can see with a single rule. Concatenate has a wide variety of uses and it is worth playing with both to visualize factors and to build interesting spreadsheets.