Aunt Sophie at the Post Office

A Maths Starter of The Day

Aunt Sophie has 5p and 9p stamps only.

It will cost 91p to post a parcel.

How many of each type of stamp should she put on the parcel?

Stamp Stamp

5p

9p

Don't miss the interactive Stamp Sticking activity.

Aunt Ann visited the post office too.

She has many 4p and 9p stamps.

What's the largest whole number amount that can't be made with Aunt Ann's stamps?

Stamp Stamp

4p

9p

Starter of The Day Transum Mathematics Topics


Topics: Starter | Arithmetic | Investigations | Money | Number | Tables

  • The Best Maths Class Ever 7cd/m2, King Alfreds, Wantage Oxfordshire
  •  
  • At first the starter was challenging but then it started to make sense and that was when everyone started to get the hang of it. All together we got all the answers between us. The people who got the first answer were Danny, Ryan, David, Murran, Molly, Bryony, Alicia and sir. And some others got the rest of the answers.
  • N Cox, Ipswich
  •  
  • A good starter that can be developed easily into a differentiated lesson. For example, use the minumum number of stamps, pairs of stamp values that work for all postage values (1p stamp not allowed!). What sort of pairs work for the fewest values of postage.
  • Set 1 Year 4(Mathematical Whizz Kids! ), Banks Lane Junior School
  •  
  • We found three ways to solve this problem by working systematically using multiples of 3 and 8.
    (2x8p)+(19x3p)
    (5x8p)+(11x3p)
    (8x8p)+(3x3p).
  • Transum,
  •  
  • This is an old idea but still very worthwhile even though the cost of the stamps probably isn't very realistic at today's prices. It lends itself to be extended in a number of ways in addition to those suggested by N Cox above (thanks). Please share any ways of developing this activity that might be useful to other teachers.

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 8 July | Next Day

 

Answers

Click here for the Aunt Sophie answers

The answer to Aunt Ann's problem is 23p.

The solution to this type of problem for a given set of stamp values is called the Frobenius number of the set. The Frobenius number exists as long as the set of coin denominations has no common factor greater than 1.

The formula for the Frobenius number when there are only two different stamp values, x and y is: xy − x − y

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 the button above to regenerate another version of this starter from random numbers.
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:

Transum.org/go/?Start=July8

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 an interactive stamp sticking activity.

Transum.org/go/?to=Sticking

Student Activity

 

For Students:

 

For Teachers:

For All:

Transum.org is a proud supporter of the kidSAFE Seal Program
©1997-2024 WWW.TRANSUM.ORG