Idea 2of 23Builds onA letter holds a number
A variable can change
Can a letter stand for different numbers?
Today you'll discover
- why n can be 1, 2, 3 or 4
- how the total changes with n
- how much the total grows each time
Think firstTwo boxes of n muffins, and 1 extra
The box size changes from day to day. Can n stand for a different number each day?
Decide first, then press Next. Watch what happens to the total when n changes.
Two boxes marked n and 1 loose cube. Then the expression 2n + 1, then the boxes opened to show 3 each, and a table: n is 1, 2, 3, 4 and 2n + 1 is 3, 5, 7, 9.
See the whole ideathe big idea and the key word, in one place
The big idea
A variable can change: each value of n gives the expression a new value.
Where it goes nextPatterns & Rules used x for the week number. The week changed, so the money changed: a variable that changes.
Easy to get wrongThe number in front, the 2 in 2n, stays the same. Only the letter's value changes.
Key word
- value
- the number a variable stands for at one time: when n = 3, its value is 3
Ready to use it?
- Work out an expression for several values of its letter.