Standard form – Year 9 maths lesson

Lesson 4 of 38 in the Year 9 maths course

UK version. UK school years, UK spelling and pounds (£). · US Math Department

A complete 45-minute lesson for Year 9 (ages 13–14) that runs on this page – at school or at home. Every answer is marked straight away, with a worked explanation.

Time: 45 minutes + 20 min homework
Year: Year 9 (ages 13–14)
You need: Paper, a pencil and this page
Marked: 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 marked straight away with a worked explanation, so you never have to mark 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: “Why is 12 × 10⁵ not in standard form?”
Later that day or the next day: the homework (20 minutes), then a practice test.

Watch out for

Writing 45 × 10³ as an answer. The front number must be less than 10: 4.5 × 10⁴.
Giving 0.0036 the power +3. Small numbers have negative powers: 10⁻³.

Tip for home: Look up distances in space or sizes of tiny things and write them in standard form.

What your child will learn

We are learning to write very large and very small numbers in standard form and calculate with them.

Success looks like

I can write numbers in standard form.
I can convert back to ordinary numbers.
I can multiply and divide in standard form.

Key words

power of ten: 10 multiplied by itself, such as 10³ = 1,000
index: the small number showing the power
negative power: a power for numbers less than 1
adjust: rewrite so the front number is between 1 and 10

What to have ready

Paper and a pencil
This page on a computer, tablet or phone
For the hands-on part: Order the sizes of planets, cells and atoms written in standard form.

The big ideas (for the adult)

A number in standard form is A × 10ⁿ, where A is at least 1 and less than 10: 45,000 = 4.5 × 10⁴.

Small numbers have a negative power: 0.0036 = 3.6 × 10⁻³.

To multiply, multiply the front numbers and add the powers; then adjust so the front number is between 1 and 10.

The lesson, step by step

45 minutes in 5 parts
Part	Time	How it is checked
Starter: quick recall	5 min	Marked by Classfern
Teaching input	10 min	Not assessed, self-checked
Worked examples and guided practice	9 min	Not assessed, marked by Classfern
Independent practice	15 min	Marked by Classfern
Plenary and exit ticket	6 min	Marked by Classfern, self-checked

Starter, "your turn", practice and exit ticket are marked 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 marked instantly.

More practice

All Year 9 maths lessons and tests · Maths Department

More Year 9 maths lessons

Curriculum

National Curriculum for England, Year 9: “interpret and compare numbers in standard form A x 10^{n} 1≤A<10, where n is a positive or negative integer or 0”

National Curriculum for England, Year 9: “understand and use place value for decimals, measures and integers of any size”

Contains public sector information licensed under the Open Government Licence v3.0.

Our lessons and questions are our own. They are not written or endorsed by any government department, testing agency or exam board.