Idea 3of 23Builds onA letter holds a number
3n means 3 times n
What does 3n mean?
Today you'll discover
- what the 3 in 3n counts
- why 3n is not 34
- how to work out 3n
Think firstThree bags, the same number in each
Each bag holds n = 4 marbles. What is 3n?
Decide first, then press Next. Count the groups, then what is in each.
Three bags marked n. Then the expression 3n with the label 3 bags: 3n. Then the bags opened to show 4 in each, and the working 3 × 4 = 12. The last step shows five bags of n beads.
See the whole ideathe big idea and the key word, in one place
The big idea
3n means 3 times n: 3 groups with n in each.
Compare them3n is 3 × n. n + 3 is n and 3 more. When n = 4, 3n is 12 and n + 3 is 7.
Easy to get wrong3n is never 3 and n side by side. When n = 4, 3n is 12, not 34.
Key word
- coefficient
- the number in front of a letter, like the 3 in 3n; it multiplies the letter
Ready to use it?
- Work out 3n, 5n or 8n for a given n.