Class 7 Mathematics — Chapter 7: FINDING THE UNKNOWN

What you'll learn

• ▸Understanding Equations and Unknowns
• ▸Framing Equations from Context
• ▸Solving Equations by Trial and Error
• ▸The Balancing Method for Solving Equations
• ▸Using Inverse Operations to Isolate Variables
• ▸Solving Multi-Step Linear Equations
• ▸Solving Equations with Variables on Both Sides
• ▸Checking the Solution of an Equation

Chapter Summary

--- PAGE 1 --- 7 FINDING THE UNKNOWN 7.1 Find the Unknowns Unknown Weights We have a weighing scale that behaves as follows. The numbers represent same units of weight: ? Find the unknown weights in the following cases: Fig. 7.1 Fig. 7.2 Fig. 7.3 --- PAGE 2 --- Finding the Unknown Fig. 7.4 Fig. 7.5 Fig. 7.6 Fig. 7.7 Fig. 7.8 ? Discuss the answers with your classmates. Give reasons why you Math think your answer is right. Talk ? Find the unknown weight of the sack in the following cases. In Fig. 7.10, all the sacks have the same weight. Fig. 7.9 Fig. 7.10 [Hint: If we remove equal weights from both the plates, will the weighing scale still be balanced? Remove one sack from ea…

Practice Questions from this Chapter

Tap "Get Solution" on any question to ask our AI tutor.

1. Discover how ancient Egyptians found unknowns. Get Solution →
2. Show real-world examples of balanced equations. Get Solution →
3. Create new matchstick patterns using equations. Get Solution →
4. According to the text, what is a statement of equality between two algebraic expressions called? Get Solution →
5. In the equation 2n + 1 = 99, what does 'LHS' stand for? Get Solution →
6. What is the formula given for the number of matchsticks in the n-th position of the sequence shown on page 4? Get Solution →
7. The method of substituting different values for a variable until the equation is balanced is called what? Get Solution →
8. What happens to a balanced equation if you perform the same operation, like addition, on both sides? Get Solution →

Did you know?

• 💡 The word "algebra" comes from an Arabic word meaning "the reunion of broken parts."
• 💡 Ancient Egyptians used basic algebra over 3,500 years ago to manage resources.
• 💡 The "equals" sign (=) was invented in 1557 by Robert Recorde to avoid writing "is equal to."
• 💡 Zero wasn't always a number; its invention revolutionized the way we solve equations.
• 💡 Equations are like a perfectly balanced seesaw, where both sides must always hold equal weight.

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