Tools

Drag the numbers into the yellow circles so that the totals along each side of the triangle are the same.

Once you have completed the above challenge, can you then rearrange the numbers so the total of each side is now different to your first solution. How many ways can this be done?

Now try this version:

Drag the numbers into the yellow circles so that the totals along each side of the triangle are the same.

Here are some more challenging, self checking, versions of this activity using:

What if there were nine digits to place on the sides of the triangle? See Triside Totals:

Starter of The Day Transum Mathematics Topics

Topics: Starter | Arithmetic | Investigations | Puzzles

Clue Giver,
Easy! Clue: 1st triangle= 9, 2nd= 18.
Jules, Devon
Brilliant.Got 12 on each side on the first one, 21 on each side for the second. If the children get stuck tell them to use the highest three numbers on the corners, bit of jigging and it always works.
Kashyap, Mt Roskill Intermediate, Auckland
Simple, either place the biggest three in the corners or the middle of the triangle, after that its easy.
Mathemaniac, South Wales
This can be used to demonstrate reflection and rotation (to get different triangles) and inversion (take each number from your first solution from 7).
Transum,
Don't miss the link below ('Transum.org/go/?to=Tools') which leads to a self-checking version of this activity for which pupils can earn trophies! One for each of the six levels. There is a method or strategy for solving this kind of puzzle and it is only when pupils have solved a number of different versions of the puzzle does the method become apparent.
Edward, Bolton
Nice activity great fun.
Mr Gray, Twitter
Second primary 7 induction day. They worked through this @Transum starter, discussed possible stratagies and different solutions before trying some similar #donsteward number problems. A bunch of them even asked to take a copy of the sheet away! pic.twitter.com/zDgXI7eQfa
— Mr Gray (@BucksburnMaths) June 13, 2019

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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Answers

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There is a printable worksheet to go with this activity.

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Teacher, do your students have access to computers such as tablets, iPads or Laptops? This page was really designed for projection on a whiteboard but if you really want the students to have access to it here is a concise URL for a version of this page without the comments:

Transum.org/go/?Start=June13

However it would be better to assign one of the student interactive activities below.

Laptops In Lessons

Here is the URL which will take them to a student version of this activity.

Transum.org/go/?to=tools

A Mathematics Lesson Starter Of The Day

Once you have completed the above challenge, can you then rearrange the numbers so the total of each side is now different to your first solution. How many ways can this be done?

Now try this version:

Here are some more challenging, self checking, versions of this activity using:

What if there were nine digits to place on the sides of the triangle? See Triside Totals:

Answers