Arrange the ornaments in the box so that no more than
three are in any line horizontally, vertically or diagonally.

Teacher: There are also self-checking versions of this activity for different sized grids:
2 by 2 3 by 3 4 by 4 5 by 5

## A Christmas Mathematics Lesson Starter Of The Day

Share

Topics: Starter | Puzzles | Xmas

You can find many more ChristMaths activities at:

Transum.org/ChristMaths/

• Rachael, Kirsty and Ewan, Leswalt Primary
•
• We really enjoyed doing this.
• Katie Lumsdaine F2 High School Of Dundee, High School Of Dundee
•
• It was challenging but fun and we could use this method to decorate our Christmas tree! :).
• Transum,
•
• After solving the problem for the 4 by 4 grid (not forgetting to check the diagonals) investigate how many different solutions there are. Extend to a 5 by 5 grid and then consider how many ornaments could be arranged on an n by n grid if each column, row and diagonal must contain one empty space.
• Mr Shepherd, St Lawrence Academy, Scunthorpe
•
• 7set4 and 9set4 really enjoyed this, given a minute each and a default fail as soon as a line was completed. We managed to get 14 pupils involved in a 10 minute slot. Exetending to how many possible solutions was beyond them though.

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.

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 3.3 out of 5 based on 312 votes.

Previous Day | This starter is for 11 December | Next Day

There is a printable worksheet to go with this activity.

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.

## 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. 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=December11

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

Transum.org/go/?to=xmas

OR

Investigate other sized ornament boxes using a spreadsheet.

Use "1" to represent an ornament in the box.

Set up row and column totals to check whether your solution is correct

For Students:

For All: