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Grade 1 · lesson 4 of 4

Find the Number That Balances an Equation

Calculate the complete side and keep that total visible.

About 15 minutes, plus any extended practice

Download the grade pack

Supplied materials

  • Paper and a pencil; drawing and spoken explanations are welcome. An adult may read directions and options aloud.
  • Supplied worked-case record: Solve 7+4 = 8+__ .
  • All quantities and shape descriptions are supplied in the worked example and questions; no purchase or personal information is needed.

Learn the idea

An equation can have a missing amount on either side. First determine the value of the complete side. Then find the missing part that makes the other side equal to it. The equal sign describes a relationship, not a signal to perform every operation in a row.

Calculate the complete side and keep that total visible. Use the known part on the other side to find the missing amount. Substitute the answer and verify that both sides name the same total.

Evaluate the complete side first. The blank may be a part, rather than the entire total. Write each side’s total beneath its expression after substituting your answer.

  1. Write each side’s total beneath its expression after substituting your answer.
  2. Follow the worked example. Point to each number or shape feature and say what it tells you.
  3. Calculate the complete side and keep that total visible.
  4. Try the question and then the three practice questions. Check your answers and explain any change you make.
Worked example

See the method in action

Solve 7+4 = 8+__ . The complete left side is 11. Eight needs three more to reach eleven, so the blank is 3. Checking both sides gives 11=11. Writing 11 in the blank would incorrectly make the right side nineteen. Evaluate the complete side first. The blank may be a part, rather than the entire total. Write each side’s total beneath its expression after substituting your answer.

Your turn

Check your reasoning

Your answer is temporary and is not saved to an account. Download your current answer before leaving or reloading. Written work on paper or in another app stays in your own file.

Helpful tips
  • Evaluate the complete side first.
  • The blank may be a part, rather than the entire total.
Find the blank: 4+5 = 6+__.

Feedback appears here after you check. This is practice, not a graded school assessment.

See the answer and explanation

3

Both sides must have the same total. The result is 3.

Take it further

Solve 9+6=10+__. Expected: 5.

Nothing here is saved to an account or sent to a teacher. The answer download includes your current choice and any checked feedback. It does not include choices from the separate More practice section. Download that section separately.

More practice: try new cases

Choose an answer for each problem. Explain your method on paper, then use the feedback to decide what to revisit.

More practice: try new cases
1. Find the blank: 5+5 = 7+__.
Need a hint?
  • Evaluate the complete side first.
  • The blank may be a part, rather than the entire total.
2. Find the blank: 6+5 = 8+__.
Need a hint?
  • Evaluate the complete side first.
  • The blank may be a part, rather than the entire total.
3. Find the blank: 7+5 = 9+__.
Need a hint?
  • Evaluate the complete side first.
  • The blank may be a part, rather than the entire total.

Your choices are temporary. Feedback appears after you check all the answers.

Nothing here is saved to an account or sent to a teacher. Keep your own notes or download them before leaving. The score describes these questions; it does not certify subject mastery.

Check the subject sources

These LifeStarter passages, scenarios and exercises are authored for this Academy with AI assistance and review. External resources keep their publishers’ terms. A grade label suggests a starting level; it does not establish alignment with your school’s complete requirements.