Remember, a letter simply represents a number in algebra.
Sometimes this may be set but sometimes it is up to you to work out what the number is worth.
Where a number can change is called a variable.
In this activity, all of the answers must be whole numbers or zero.
x + 3y = 8
What do we know?
What is set and what can't be changed?
What are we in control of? Why are these variables?
Through trial and error, we can find options:
The 3 different combinations can be shown in a bar model