What Are They?

1. The product of two odd numbers is 357.

What are they?

2. The difference between two square numbers is 21.

What are they?

3. The sum of three prime numbers is 29.

What are they?

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

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!
  • Transum,
  • Click on one of the gold stars below and you will see a bar chart showing how people scored this starter. At the time of writing there were exactly the same number of votes for one as there were for five. This is probably because this starter requires a knowledge of some particular terms and concepts and some pupils will have this knowledge while others are too young to be expected to understand. Originally these starters were aimed at Secondary/High school pupils but they are commonly accessed by Primary school pupils, some only in Year 2!
    If you are one of the teachers who scored this page a one, have a look at some of the other starters as there is probably something that will suit your class. There are 366 Starters Of The Day with some additional Advanced Starters being added this month.

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This starter has scored a mean of 3.0 out of 5 based on 409 votes.

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1. 1 and 357 or 3 and 119 or 7 and 51 or 17 and 21 (and their negatives).

2. 4 and 25 or 100 and 121. Could there be any other solutions?

3. 3, 3 and 23 or 3, 7 and 19 or 3, 13 and 13 or 5, 5 and 19 or 5, 7 and 17 or 5, 11 and 13 or 7, 11 and 11.

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


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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

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Student Activity



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