A Mathematics Lesson Starter Of The Day

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:

the digits 2 to 7 the digits 3 to 8 multiples of 4 negative numbers random numbers

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

Puzzle 1 Puzzle 2 Puzzle 3 Puzzle 4 Puzzle 5

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 ('') 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

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.

Previous Day | This starter is for 13 June | Next Day



Click here for a full set of answers.

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 link. As an Amazon Associate I earn a small amount from qualifying purchases which helps pay for the upkeep of this website.

Educational Technology on Amazon


Online Maths Shop

Laptops In Lessons

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:

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.

Student Activity


©1997-2024 WWW.TRANSUM.ORG