🛍️ Mystery bags
What does the letter b stand for?
Each bag holds b beads. Mia has 3 bags, so she has 3 × b beads. Is b short for “beads”? Let’s open the bags and find out.
Open the bags ↓A letter holds a number.
Press Next step. Watch what’s inside the bags.
🛍️ Mystery bagsStep 1 of 6
“b is for beads. So 3 × b means 3 beads!”
b isn’t a thing. It’s a number:
how many beads are in each bag.
how many beads are in each bag.
b =
Your turn: 5 mystery-letter challenges
Every letter is hiding a number. Find it, or use it.
🎯 Challenge0 of 5 done
⭐ You saw through the trap
A letter is a box for a number.
3 × b3 bags of b beads:
if b = 6, that’s 18
if b = 6, that’s 18
n + nsame letter,
same number
same number
b + 4 = 10open the bag:
b = 6
b = 6
In math, a letter like b or n is a variable: it holds the place of a number. It isn’t short for a word, so 3 × b isn’t “3 beads”. It’s 3 times however many b is. The number can change from one problem to the next, but inside one problem the same letter always stands for the same number.