68 can be reduced to 1 by using only the number four key and any of the operation keys.

For example:

68 - 4 = 64
64 ÷ 4 = 16
16 ÷ 4 = 4
4 ÷ 4 = 1

How many other numbers can be reduced to 1 using only the four key and any of the operation keys?

Starting number:      Calculator button:

## A Mathematics Lesson Starter Of The Day

Share
• Sue Sunn, St Albans
•
• 76 +4 = 80
80/ 4 = 20
20 / 4 = 5
5 - 4 = 1
• Francisco Schreiber, Rokeby School East London
•
• Divided by 2 is a good starting point for foundation groups.
• Miss Sidebotham, -
•
• This starter was a good one, the children loved it.
•
• Really good. Got my brain thinking...
96/4=24
24-4=20
20-4=16
16/4=4
4/4=1
•
• Sixty eight plus four plus four plus four plus four plus four plus four plus four plus four divided by four take away four take away four take away four take away four equals ONE!
• Teacher, UK
•
• Actually any number can be done this way,
Take the number a
do a x 4 = 4a
-4
-4
-4... (a-1) times
so were left with 4
then divide by 4
I think it's a reasonable starter so I rated it 2 but it needs a limit to the number of operations allowed.

How did you use this starter? Can you suggest how teachers could present or develop this resource? Do you have any comments? It is always useful to receive feedback and helps make this free resource even more useful for Maths teachers anywhere in the world.

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This starter has scored a mean of 3.2 out of 5 based on 275 votes.

Previous Day | This starter is for 15 March | Next Day

It is possible to reduce any number to one using any calculator key.

Your access to the majority of the Transum resources continues to be free but you can help support the continued growth of the website by doing your Amazon shopping using the links on this page. Below is an Amazon search box and some items chosen and recommended by Transum Mathematics to get you started.

## Have you read Craig's book yet?

Craig Barton must surely be the voice of Mathematics teachers in the UK. His wonderful podcasts interviewing the industry experts have culminated in this wonderful book. As Craig says: "I genuinely believe I have never taught mathematics better, and my students have never learned more. I just wish I had known all of this twelve years ago..." more...

"How I wish I'd taught Maths" is an extraordinary and important book. Part guide to research, part memoir, part survival handbook, it’s a wonderfully accessible guide to the latest research on teaching mathematics, presented in a disarmingly honest and readable way. I know of no other book that presents as much usable research evidence on the dos and don’ts of mathematics teaching in such a clear and practical way. No matter how long you have been doing it, if you teach mathematics—from primary school to university—this book is for you." Dylan Wiliam, Emeritus Professor of Educational Assessment, UCL.

## Casio Classwiz Calculator

There is currently a lot of talk about this new calculator being the best in its price range for use in the Maths classroom. The new ClassWiz features a high-resolution display making it easier to view numerical formulas and symbols but it isn't a graphical calculator as such (it has the capacity to draw graphs on your smart phone or tablet, via a scannable QR code and an app).

As well as basic spreadsheet mode and an equation solving feature you also get the ability to solve quadratic, cubic or quartic polynomial inequalities and the answer is given just as it should be written down, using the correct inequality symbols!

This calculator has a high-performance processor and twice the memory of previous models ensuring speedy operation and superior computational power.more...

## Hello World

You are buying a (driverless) car. One vehicle is programmed to save as many lives as possible in a collision. Another promises to prioritize the lives of its passengers. Which do you choose?

Welcome to the age of the algorithm, the story of a not-too-distant future where machines rule supreme, making important decisions – in healthcare, transport, finance, security, what we watch, where we go even who we send to prison. So how much should we rely on them? What kind of future do we want?

Hannah Fry takes us on a tour of the good, the bad and the downright ugly of the algorithms that surround us. In Hello World she lifts the lid on their inner workings, demonstrates their power, exposes their limitations, and examines whether they really are an improvement on the humans they are replacing.

This calculator has a high-performance processor and twice the memory of previous models ensuring speedy operation and superior computational power.more...

 Teacher, do your students have access to computers?Do they have iPads or Laptops in Lessons? Whether your students each have a TabletPC, a Surface or a Mac, this activity lends itself to eLearning (Engaged Learning).

Transum.org/go/?Start=March15

Here is the URL which will take them to a related student activity.

Transum.org/go/?to=Bidmaze

## And now for something completely different.

The 15th March is referred to as the 'ides of March' in a Shakespeare play. The date was notorious as the date of the assassination of Julius Caesar in 44 BC. The death of Caesar made the Ides of March a turning point in Roman history.

You can find more about the word ides in the comments of the Roman Numerals Starter.

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