What Are They?

1. The product of two odd numbers is 91.

What are they?

2. The difference between two square numbers is 12.

What are they?

3. The sum of three prime numbers is 25.

What are they?

4. The ratio of two even numbers is 5:7.

What are they?

A Mathematics Lesson Starter Of The Day

Topics: Starter | Arithmetic | Number | Puzzles | Ratio

  • C. J. Southward, Limehouse Cumbria
  • In the product question the solutions do not include the double negative
  • Transum,
  • Thanks CJ. That has now been allowed for in the answers below.
  • 6N, Charnwood Primary School
  • We really enjoyed this and some of us thought it was easy - However we haven't tried the hard numbers yet!
  • Ms Robyn, ABCIS In Vietnam
  • This was fun, the harder numbers made us think! We were very pleased that some of us managed to get the product answer to the 'hard' level without a calculator.

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 4 June | Next Day



1. 1 and 91 or 7 and 13 (and their negatives).

2. 4 and 16. Could there be any other solutions?

3. 3, 3 and 19 or 3, 5 and 17 or 3, 11 and 11 or 5, 7 and 13 or 7, 7 and 11.

4. 10 and 14 or 20 and 28 or 30 and 42 or ...


Note to teacher: Doing this activity once with a class helps students develop strategies. It is only when they do this activity a second time that they will have the opportunity to practise those strategies. That is when the learning is consolidated. Click a button below to regenerate another version of this starter from random numbers.

Easy Medium Hard

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 related student activity.


Student Activity



©1997-2024 WWW.TRANSUM.ORG