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.
• Ashwin, India
•
• Important tip:- you can the digit twice as well like 44 -).

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This starter has scored a mean of 3.1 out of 5 based on 832 votes.

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

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

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 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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