# Hole in One

## Starter of The Day

If six girls can plant 90 trees in a day, how many trees can ten girls plant in a day?

If five men can dig a hole in one hour, how long will it take two men to dig half a hole?

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Topics: Starter | Arithmetic | Problem Solving | Ratio

• Petro Els, Greenmeadows School, NZ
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• Cool idea. Worked magic. . . THANKS!
• Rawthorpe High School, Mr Heeley's Y7 brainboxes
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• Ha ha, you had us fooled! We think, however, that theoretically the answer would be 75 mins. We can't believe you've tricked us like this. I now want to find a whole hole (or half a hole!) to jump in and hide from my clever pupils!
Happy Easter, love set 1 in da Hud xx
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• Really cool. Very good trick and wasn't expecting it!
• Mrs Cooper, AHS
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• Most of my class realised that it was a trick. However they also worked out 1 hour and 15 mins. 8Y.
• 7cd/M2, King Alfred's College Oxfordshire
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• Liam and Louis figures you can't dig half a hole ! But the rest of us fell in it!!
For the 2nd question, we thought the answer would be: 1 man takes 5 hours so 2 men take 4 hours. So for half a hole it would take 2 hours.
• Bona, King George V School
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• It's a really good question.150 trees and you can't dig half a hole!
• Year 6, Tickhill St. Mary's
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• We think it would take 2 men a fortnight to dig half a hole...because it would take them that long to work out that you can't dig half a hole! ;).
• Lauren Cowie, High School Of Dundee
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• You tricked us and it is really strange because each day you seem to choose a topic that we are doing in class :D.
• Miss Reakes, West Island School
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• Not one of my set 2 Yr10 class made the leap to realising there is no such thing as half a hole! Then we went on to discuss how not to take everything at face value. Classic starter!
The students struggled with the concept of half a whole not existing... The word volume would need to be added. Maybe they just didn't like to be tricked......!!!!
• Mr Kavanagh's Fifth Class, Cork, Ireland
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• Our class feels that if the sum specifies a quantity (i.e. the hole) as x then half a hole would be x/2 and so mathematically the question does make sense. The answer is 1 hour and fifteen minutes.
• Amber, Wellfieldcommunityschool
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• I found that they would plant 150 trees but you can't dig half a whole can you?
• Tnorf, Manchester
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• After some deep discussion and debate. We think it takes 1 man 5 hours to dig a 1 hole (whole); therefore it takes 2 men 2.5 hours to dig a full hole and it takes them half the time to dig half a hole so 1.25 hours???? I hope it's a trick question LOVED the debate oot caused! !

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## Extension

 If a hen and a half, lays an egg and a half, in a day and a half. How many eggs will 9 hens lay in 6 days?

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## 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

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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=March19

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

Transum.org/go/?to=unitary