Simple Equations for Class 7: Transposition Explained with Worked Examples

Class 7 simple equations made simple — the transposition method explained step-by-step with three worked examples and free printable practice worksheets aligned to NCERT.

If your Class 7 child has been staring at "x + 7 = 12, find x" and asking "मैं कैसे शुरू करूँ?", you are in the right place. Simple equations look scary because of the letter — but at heart they're just a balance puzzle. This article breaks down the two methods CBSE Class 7 teaches (balance method and transposition) and then walks through three worked examples.

Pair this with our dedicated Simple Equations Class 7 topic page — it has ready-to-print worksheets with answers.

What is a "simple equation"?

An equation is a statement of equality — two sides of an "=" sign that must always be equal. A simple equation has:

one variable (usually x or y),
with power 1 (no x², no √x),
and no fractions inside brackets.

Example: 2x + 3 = 11. Here x is the unknown. Our job: find the number that, when we plug it in for x, makes both sides equal.

Method 1 — The Balance Method (concept)

Think of the "=" sign as the middle of a तराज़ू (balance). Whatever we do on the left, we must do the same on the right — otherwise the balance tips over.

Rule: Whatever operation you perform on one side, perform the same operation on the other side.

Method 2 — Transposition (the shortcut)

Transposition is just the balance method done fast. The rule is one line:

When a term moves across the "=" sign, its operation reverses.

+ becomes − (and vice versa)
× becomes ÷ (and vice versa)

That's it. This is the method CBSE Class 7 marks-schemes prefer for full credit.

Worked Example 1: `x + 7 = 12`

Goal: get x alone on the left.

+7 is stuck to x. Move it across "=" — it becomes −7.

x = 12 − 7
x = 5

Verification: Put x = 5 back in: 5 + 7 = 12. ✅

Worked Example 2: `3y = 21`

3 is multiplied by y. Move it across "=" — multiplication becomes division.

y = 21 ÷ 3
y = 7

Verification: 3 × 7 = 21. ✅

Worked Example 3: `2x − 5 = 11` (two-step)

Here two things are attached to x: subtract 5, and multiply by 2. Undo them in reverse order — addition/subtraction first, then multiplication/division.

Step 1 — move −5 across:

2x = 11 + 5
2x = 16

Step 2 — move 2 (multiplication) across as division:

x = 16 ÷ 2
x = 8

Verification: 2 × 8 − 5 = 16 − 5 = 11. ✅

Word problem: "Five times a number is 45. Find the number."

Let the number = x.

5x = 45
x = 45 ÷ 5
x = 9

Word problems are 80% about converting the sentence into an equation. Once the equation is on paper, transposition finishes it in 2 lines.

The 3 mistakes Class 7 kids make

Forgetting to change the sign. Moving +7 across and writing +7 again on the other side. Rule: cross the =, flip the sign.
Doing multiplication and addition in the wrong order. Always undo + / − first, then × / ÷.
Skipping verification. 30 extra seconds. Catches almost every silly error.

Home practice plan (2 weeks)

Week 1: 5 one-step equations a day (like Example 1 & 2). Focus on sign flip. Week 2: 5 two-step equations a day (like Example 3). Add 2 word problems on weekends.

That's 70 equations in a fortnight — enough for Class 7 confidence.

Print worksheets from the Simple Equations Class 7 topic page. Every sheet has an answer key on the last page, so your child can self-check.

FAQ

Q. Should I let my child use the balance method or transposition? Both. Understand balance conceptually, use transposition on paper. CBSE examiners accept either — transposition is just faster.

Q. My child gets the answer but the teacher cuts marks. Why? Class 7 marking rewards shown steps. Encourage writing at least 2 lines: rearranged equation, then final value. Verification adds a bonus mark on many rubrics.

Q. Are word problems always in the exam? Yes — usually 1–2 questions. That's why the "convert sentence to equation" skill matters more than pure calculation.

Q. What comes after simple equations? Linear equations in Class 8 (with brackets and fractions). Master transposition now and Class 8 is easy.