Solve the Addition Equation: Finding the Missing Number in -3 + ? = 5

Addition Equations with Negative Starting Values

3+(?)=5 -3+(?)=5 -5-5-5-4-4-4-3-3-3-2-2-2-1-1-1000111222333444555

❤️ Continue Your Math Journey!

We have hundreds of course questions with personalized recommendations + Account 100% premium

Step-by-step video solution

Watch the teacher solve the problem with clear explanations
00:00 Complete the missing part
00:03 The number is directed and negative
00:09 The negative direction on the axis is left, so we'll take 3 to the left
00:15 This is the desired number, let's find it on the axis
00:26 Let's find its distance from point (-3)
00:36 The direction of progress is to the right (positive)
00:45 And this is the solution to the question

Step-by-step written solution

Follow each step carefully to understand the complete solution
1

Understand the problem

3+(?)=5 -3+(?)=5 -5-5-5-4-4-4-3-3-3-2-2-2-1-1-1000111222333444555

2

Step-by-step solution

To find out how much we need to add to the number negative 3 in order to get 5, we will count the number of steps between the two numbers.

Also, we will pay attention to which direction we moved, if we moved to the right then the number is positive, if we moved to the left the number will be negative.

We will start from the number negative 3, and move to the right until we reach the number 5, with each step representing one whole number, as follows:

-5-5-5-4-4-4-3-3-3-2-2-2-1-1-1000111222333444555

We discover that the number of steps is 8. Since we moved to the right, the number is positive

3

Final Answer

8 8

Key Points to Remember

Essential concepts to master this topic
  • Rule: To solve -3 + ? = 5, find what makes the equation true
  • Technique: Count steps from -3 to 5 on number line: 8 steps right
  • Check: Substitute back: -3 + 8 = 5 ✓

Common Mistakes

Avoid these frequent errors
  • Confusing direction when counting on number line
    Don't count backwards from -3 to 5 = wrong negative answer! Moving from a negative number to a positive number always means going RIGHT (positive direction). Always count the steps moving right from -3 to reach 5.

Practice Quiz

Test your knowledge with interactive questions

a is negative number.

b is negative number.

What is the sum of a+b?

FAQ

Everything you need to know about this question

Why do I need to use a number line for this problem?

+

The number line helps you visualize the distance and direction between -3 and 5. It shows clearly that you need to move 8 steps to the right, which means adding a positive 8.

How do I know if the missing number is positive or negative?

+

Look at the direction you move on the number line! Moving right means the number is positive, moving left means negative. Since -3 to 5 goes right, the answer is positive.

Can I solve this without counting every step?

+

Yes! You can think: "What do I add to -3 to get 5?" This becomes 5(3)=5+3=8 5 - (-3) = 5 + 3 = 8 . Both methods give the same answer!

What if I accidentally count the wrong direction?

+

If you count left instead of right, you'll get -8 instead of 8. Always check your answer by substituting: -3 + (-8) = -11, not 5, so you know it's wrong!

Why does the number line show colored dots?

+

The colors help identify negative numbers (red), zero (blue), and positive numbers (green). This visual coding makes it easier to see the pattern and direction of movement.

🌟 Unlock Your Math Potential

Get unlimited access to all 18 Signed Numbers (Positive and Negative) questions, detailed video solutions, and personalized progress tracking.

📹

Unlimited Video Solutions

Step-by-step explanations for every problem

📊

Progress Analytics

Track your mastery across all topics

🚫

Ad-Free Learning

Focus on math without distractions

No credit card required • Cancel anytime

More Questions

Click on any question to see the complete solution with step-by-step explanations