Coins On The Table

Coin Coin Coin Coin Coin Coin Coin Coin Coin Coin Coin

Some coins were arranged in a row.
Half of them were tails up.
Two of the coins are turned over and now one third of them are tails up.
How many coins were in the row?

Coin Coin Coin Coin Coin Coin Coin Coin Coin Coin Coin

Teacher: Here is a visual aid to use if required. Coins can be dragged and, to turn them over, doubleclick.

Have a guess!


Share

Topics: Starter | Fractions | Problem Solving | Puzzles

  • Mrs A Milton, Ysgol Ardudwy
  •  
  • I have used your starters for 3 years now and would not have a lesson without one! Fantastic way to engage the pupils at the start of a lesson.
  • The Best Maths Group Ever 7cd/M2, King Alfred's College, Oxfordshire
  •  
  • Some of us caught on quickly. But majority found it tricky. Drawing coins helped to explain the answer.
  • Rachel, Claverham
  •  
  • You should have been more specific with the wording and said that the tails were turned over.
  • Francis, Halifax
  •  
  • The wording of the question is fine. If 1/2 of the coins start as tails up, and, when 2 are turned this becomes 1/3, it should be obvious that it was tails that were turned because 1/3 is less than 1/2.
  • Gabriel, Edgware
  •  
  • The wording is a problem...
    If you started with 6 coins and turned one head and one tail over, you would get to 1/2 and 1/3.
    Surely?
  • Primary 7, Bargeddie Primary School
  •  
  • The majority of our class found this very confusing at first. However, Lewis in our class worked out the answer very quickly: he worked out that if he thought of a number on the 2 times table, and tried to take 2 away to see if it was on the three times table then he would have his answer...
    The rest of the class were most impressed!
  • Nick, Weston
  •  
  • This was epic.
  • Sarah, Tenbury
  •  
  • I think your algebraic answer is harder than it needs to be. if you say
    x/2 - 2 = x/3 (+2 and -x/3 on both sides then

    x/2 - x/3 = 2 (x6 both sides)
    3x - 2x = 12 so x=12.
  • Mr Miller, Brough Primary
  •  
  • One child in our class found this particularly confusing but she eventually understood after much discussion and debate with the teacher!
    Everybody else found it interesting, if not challenging.
  • Holly Walton, Calmore Junior School
  •  
  • Really good website.
  • Matthew Zhao, 5S, Craigslea State Primary School
  •  
  • Challenging for average grade 5s, although very easy for my intelligent brain and my quick way of using Trial and Error. =).

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.
Click here to enter your comments.

If you don't have the time to provide feedback we'd really appreciate it if you could give this page a score! We are constantly improving and adding to these starters so it would be really helpful to know which ones are most useful. Simply click on a button below:

Excellent, I would like to see more like this
Good, achieved the results I required
Satisfactory
Didn't really capture the interest of the students
Not for me! I wouldn't use this type of activity.

This starter has scored a mean of 3.1 out of 5 based on 260 votes.


Previous Day | This starter is for 16 March | Next Day

 

Answers



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...

Online Maths Shop

Laptops In Lessons

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).

Laptops In Lessons

Here a concise URL for a version of this page without the comments.

Transum.org/go/?Start=March16

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

Transum.org/go/?to=Equivalent

Student Activity

 


Do you think a fraction wall might help with this puzzle?


Apple

©1997-2017 WWW.TRANSUM.ORG