What is the price at the question mark?
The symbols above are direct references to what they mean, but we can use any symbols we like. If is the cost of a cup of cocoa and is the cost of one cone of ice cream, the first two lines above are equivalent to
and here are both variables, values that can vary and are only fixed to set numbers in order to fulfill the specific conditions of the problem.
Micah has Sara has If Micah gives some money to Sara, how much does Micah need to give so at the end they both have the same amount of money?
The prior problem could be represented with the variable being the amount of money given:
- Micah starts with and loses so she has at the end
- Sara starts with and gains so she has at the end
In other words, the problem was to find such that
Three squares each contain an identical number of dots.
How many dots should go in each square so that the squares have a combined total of dots?
The count of dots per square is acting as a variable. Not only is it an amount that can vary but it can also be reused, and each instance of the variable represents the same number of dots.
With letters, we could assign the number of dots as and the previous question is asking when
equals
We can also simplify into which is considered equivalent.