---
title: "Trial balance errors: when balanced isn't right"
course: "ACCT 150 · Read the numbers of a business"
unit: "Month one: keeping the books in a spreadsheet"
lesson: 7 of 43
source: https://open.maestrocollege.edu/read-the-numbers-of-a-business/trial-balance-errors-when-balanced-isn-t-right
publisher: Maestro College
---

# Trial balance errors: when balanced isn't right

Lesson 7 of 43 in **Read the numbers of a business** (ACCT 150), unit "Month one: keeping the books in a spreadsheet". An open lesson from Maestro College.

## What the learner will be able to do
- Find errors that throw a trial balance out of balance, such as transposed digits, one-sided postings, and balances in the wrong column.
- Find errors that leave a trial balance in balance, such as a wrong account, an omitted entry, or a duplicated entry, by tracing figures back to source documents.
- Fix each error at its source and confirm the corrected trial balance.

## Teaching notes
Give the learner a journal and trial balance with four planted errors: two that unbalance the trial balance (for example, 1,700 keyed as 1,070) and two that leave it balanced (a wrong account and a duplicated entry). In Unit 1 errors are fixed by editing the original line; correcting entries arrive in Unit 2.

## Course teaching approach
- Start from a real-world problem, then introduce the concept as the solution.
- Keep it true beginner level, hands-on, a little gamified. The learner should feel they are winning.
- Balance explanation, demonstration and practice. No copy-paste exercises: give small story-based tasks.
- End with one fun closed question about the topic.

## How to use this document
You are acting as a tutor for a learner on Maestro Open. Teach from this document, one small step at a time. Ask the learner to try things, wait for their answer, then give feedback. Keep it beginner-friendly. If the lesson involves code or spreadsheets and you cannot run them, ask the learner to try it on their own computer and paste the result back. Do not award grades, credit or certificates.

## When the lesson is done
The lesson is complete only when the learner has shown they can do every outcome listed above. Check each one with a small task or question; if an answer is wrong, explain and let them try again before moving on.
When every outcome is covered:
1. Say clearly: "Lesson 7 complete: Trial balance errors: when balanced isn't right."
2. Give a two-line recap of what they learned.
3. Name the next lesson, "Your first income statement and balance sheet" (lesson 8 of 43), and give the learner its link: https://open.maestrocollege.edu/read-the-numbers-of-a-business/your-first-income-statement-and-balance-sheet.md. Tell them to paste that page into this chat, or fetch it yourself if you can open links, then start it the same way. Do not start teaching the next lesson's topic until the learner has it.

Previous lesson: The trial balance
Next lesson: Your first income statement and balance sheet