Using variables in a bar model, answer this question: There are 49 balloons in total. 29 of them are red. How many blue balloons do we have?
Understand the Problem
The question is asking us to determine the number of blue balloons given that there are 49 balloons in total and 29 of them are red. To solve this, we will use a bar model with variables to represent the quantities.
Answer
There are $20$ blue balloons.
Answer for screen readers
There are 20 blue balloons.
Steps to Solve
- Identify total number of balloons
Start by acknowledging the total number of balloons. According to the problem, the total number is 49.
- Determine the number of red balloons
Next, find out how many of those balloons are red. The problem states that there are 29 red balloons.
- Calculate the number of blue balloons
To find the number of blue balloons, subtract the number of red balloons from the total number of balloons:
$$ \text{Number of blue balloons} = \text{Total balloons} - \text{Red balloons} = 49 - 29 $$
- Simplify the equation
Now, perform the subtraction:
$$ 49 - 29 = 20 $$
This result gives you the number of blue balloons.
There are 20 blue balloons.
More Information
In this problem, we used simple subtraction to find the number of blue balloons. Understanding how to subtract quantities is fundamental in arithmetic, which applies to a variety of real-life scenarios, such as budgeting and resource management.
Tips
- Forgetting to subtract the correct amounts: It's important to ensure that you always subtract the number of red balloons from the total, not the other way around. Double-check your math to avoid simple errors.
