Mathematics

Intermediate

50 mins

Teacher/Student led

Learning Goals

Learning Outcomes

Lesson Files

+80 XP

Teacher-led from the board. Pupils do not need a device, but can follow on one.

What you need:
IWB/Projector/Large Screen

Multiplying by 10, 100 and 1000

Learn how multiplying by 10, 100 and 1000 shifts digits left whilst the decimal point stays fixed in place. Use place-value charts to see the pattern and practise with whole numbers and decimals.

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1 Getting Started
2 Watch and Notice
3 Try It Together
4 Line up the Columns in Your Copy
5 Class Challenge
6 What Did We Notice?
7 What's Next
Pupil practice

Your turn

Your teacher is running this lesson on the board. Here is the part you can try yourself.

Your written work is on page 23

Place value chart

1 - Getting Started ~4 mins

Worked example

Illustration for Getting Started Here is a spot-the-mistake. Someone worked out 47 × 10 and wrote 47.0, they added a decimal point and zero and left the digits where they were. Is that right?

Have a good look. What does 47 × 10 really equal, and what has gone wrong in this answer?

👇 Mark your steps as done as you complete them.

+5 XP

2 - Watch and Notice ~9 mins

Watch the place-value chart as we multiply by ten, a hundred and a thousand. Every time, the digits slide left and the point stays put. Watch where each digit lands and what fills the empty columns behind it.

👇 Mark your steps as done as you complete them.

+10 XP

3 - Try It Together ~11 mins

Key point

We say the answer aloud before we slide the digits, so we can check our prediction against what the chart shows.

Today we work through these together on the place-value chart, in this order: 6 × 10, then 6 × 100, then 3.5 × 10, then 3.5 × 100, and finally 3.5 × 1000. The number the chart begins with is the one we type in ourselves: it opens on 3.5, so we change it to 6 for the first two, then put 3.5 back for the last three.

Watch for

Watch how 3.5 × 10 turns a decimal into a whole number, and how 3.5 × 1000 sends the digits three columns left and fills the gaps with zeros.

Slide the digits left

+15 XP

4 - Line up the Columns in Your Copy ~3 mins

COPYBOOK MOMENT

Illustration for Line Up the Columns in Your Copy In your maths copy, write each starter and its answer one above the other, with the digits lined up by column. Then draw an arrow above each digit showing how far it slid to the left.

28 × 10
28 × 100
5.6 × 10
5.6 × 1000

Keep your columns straight so you can see exactly which column each digit moved into.

+10 XP

Pupil practice

Module 2 · Operations and Computational Fluency Number

Lesson 24 · Multiplying by 10, 100 and 1000

Download Activity Book page (PDF)

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