Unit prices and best buys – Grade 6 math lesson
Lesson 8 of 26 in the Grade 6 math course
US version. US grades, US spelling and dollars ($). · UK Maths Department
A complete 45-minute lesson for grade 6 (ages 11–12) that runs on this page – at school or at home. Every answer is graded right away, with a worked explanation.
- Time
- 45 minutes + 20 min homework
- Grade
- Grade 6 (ages 11–12)
- You need
- Paper, a pencil and this page
- Graded
- Instantly, with explanations
For parents: how to use this lesson
You don't need to know this topic yourself. The lesson explains each step on screen, one tidy step at a time. Every answer is graded straight away with a worked explanation, so you never have to grade anything.
- Read what your child will learn and the big ideas together.
- Press Start the lesson below and sit with your child for the teaching and the worked examples (about 19 minutes).
- Let them do the practice on their own. They choose Getting started, On track or Challenge – start on On track and move up after a few right in a row.
- Finish with the exit ticket and the talk question: “Is the biggest pack always the best value? When might it not be?”
- Later that day or the next day: the homework (20 minutes), then a practice test.
Watch out for
- Thinking the bigger pack is always better value. Work out the price per gram for each.
- Multiplying when converting back the other way. Ask whether the answer should be bigger or smaller.
Tip for home: Find unit prices on shelf labels together next time you shop.
What your child will learn
Learning goal: compare value for money and convert between currencies.
Success looks like
- I can find a unit price.
- I can decide which is the best buy.
- I can convert between currencies.
Key words
- best buy
- the option that gives most for the money
- unit price
- the cost of one unit
- regroup rate
- how much of one currency you get for one of another
- convert
- change to another unit
What to have ready
- Paper and a pencil
- This page on a computer, tablet or phone
- For the hands-on part: Compare two real pack sizes of the same food and find the price per 100 g.
The big ideas (for the adult)
To find the best buy, work out the price of one unit (per gram or per item) for each option, or the amount you get for one unit of money.
Make sure you compare the same units: change kilograms to grams if needed.
To convert money between currencies, multiply or divide by the regroup rate.
The lesson, step by step
| Part | Time | How it is checked |
|---|---|---|
| Starter: quick recall | 5 min | Graded by Classfern |
| Teaching input | 10 min | Not assessed, self-checked |
| Worked examples and guided practice | 9 min | Not assessed, graded by Classfern |
| Independent practice | 15 min | Graded by Classfern |
| Closure and exit ticket | 6 min | Graded by Classfern, self-checked |
Starter, "your turn", practice and exit ticket are graded by Classfern. Worked examples and teaching are not assessed. The hands-on task and the reflection are self-assessed. Explanations in talk are judged by the parent and not recorded.
The lesson
It runs here on the page. No sign-up and no names – progress is kept only in this browser.
Homework and practice at home
20 minutes: 10 practice questions, 3 multiple-choice questions and 2 to remember from earlier work, then a short reflection. New questions every time, all graded instantly.
More practice
More Grade 6 math lessons
- Solving word problems
- Fractions, decimals and percentages
- Ratios
- One quantity as a fraction or percentage of another
- Percent
- Proportional relationships
- Rates and unit rates
- Converting units
- Negative numbers and temperature
- Integers and absolute value
- Operations with multi-digit decimals
- Operations with fractions
- Greatest common factor and least common multiple
- Square and cube numbers
- Writing expressions
- Evaluating expressions
- Simplifying expressions
- Solving equations
- Inequalities
- Writing equations for situations
- 3-D shapes and nets
- Coordinates
- Volume and surface area
- Mean, median and mode
- Box plots and interquartile range
Curriculum
Common Core State Standards 6.RP.A.3.b: “Solve unit rate problems including those involving unit pricing and constant speed. For example, if it took 7 hours to mow 4 lawns, then at that rate, how many lawns could be mowed in 35 hours? At what rate were lawns being mowed?”
Our lessons and questions are our own. They are not written or endorsed by any government department, testing agency or exam board.