Skip over navigation
Cambridge University Faculty of Mathematics NRich logo
menu search
  • Teachers expand_more
    • Early years
    • Primary
    • Secondary
    • Post-16
    • Events
    • Professional development
  • Students expand_more
    • Primary
    • Secondary
    • Post-16
  • Parents expand_more
    • Early Years
    • Primary
    • Secondary
    • Post-16
  • Problem-Solving Schools
  • About NRICH expand_more
    • About us
    • Impact stories
    • Support us
    • Our funders
    • Contact us
  • search

Or search by topic

Number and algebra

  • The Number System and Place Value
  • Calculations and Numerical Methods
  • Fractions, Decimals, Percentages, Ratio and Proportion
  • Properties of Numbers
  • Patterns, Sequences and Structure
  • Algebraic expressions, equations and formulae
  • Coordinates, Functions and Graphs

Geometry and measure

  • Angles, Polygons, and Geometrical Proof
  • 3D Geometry, Shape and Space
  • Measuring and calculating with units
  • Transformations and constructions
  • Pythagoras and Trigonometry
  • Vectors and Matrices

Probability and statistics

  • Handling, Processing and Representing Data
  • Probability

Working mathematically

  • Thinking mathematically
  • Developing positive attitudes
  • Cross-curricular contexts

Advanced mathematics

  • Decision Mathematics and Combinatorics
  • Advanced Probability and Statistics
  • Mechanics
  • Calculus

For younger learners

  • Early Years Foundation Stage

Number Pattern Explorations

Age 7 to 14
Challenge Level Yellow starYellow star
  • Problem
  • Student Solutions
  • Teachers' Resources

Here is a little journey taken by one creative explorer:-

They decided on an easy start by taking:



3 x 8 + 4

The pattern went as follows:-



2 8
2 2 8
1 8 2 8
1 4 6 2 8
1 1 7 0 2 8
9 3 6 2 2 8
7 4 8 9 8 2 8
5 9 9 1 8 6 2 8
4 7 9 3 4 9 0 2 8

This was quite nice, after the first number [the chosen one] all the digits in the units column are 8, the tens are 2 and the digital roots go:- 1, 3, 1, 3, 1, 3, 1, 3, 1.

So what happened when the starting number is changed?



4 x 8 + 4


 
4
3 6
2 9 2
2 3 4 0
1 8 7 2 4
1 4 9 7 9 6
1 1 9 8 3 7 2
9 5 8 6 9 8 0

And the digital roots now go:- 9, 4, 9, 4, 9, 4, 9, 4

Whoa! That's quite something. The units now go, after the first chosen number, 6204 and repeat.

Well let's summarize what the rest of the exploration gave :-

RULE UNITS DIG.ROOTS OTHER COMMENTS
3 x 8 + 4 8.... 1 3 1 3 1 3 ... Tens > 2 Hunds > 2860....
4 x 8 + 4 6204 ... 9 4 9 4 9 4 ...
5 x 8 + 4 4260 ... 8 5 8 5 8 5 ...
6 x 8 + 4 2046 ... 7 6 7 6 7 6 ...
7 x 8 + 4 0462 ... 6 7 6 7 6 7 ...
8 x 8 + 4 8... 5 8 5 8 5 8 ... Tens > 6480
9 x 8 + 4 6204 ... 4 9 4 9 4 9 ...
10 x 8 + 4 4620 ... 3 1 3 1 3 1 ... So we could predict that the next ones go:-
11 x 8 + 4 2 ... 2 ... Dig. Roots should be 2, 11 but 11 is 2 so all are 2!
12 x 8 + 4 0462 ... 1 3 1 3 1 3 ...
13 x 8 + 4 8 ... 9 4 9 4 9 4 ... Checked, and Tens > 0648....

Well reading this has been very exciting and led Bernard to make a further change, using 7 instead of 8.

RULE UNITS DIG.ROOTS OTHER COMMENTS
2 x 7 + 4 8024... 945378612 .. Tens > 1310 ...
3 x 7 + 4 5973... 786129453 .. Tens > 2750 ...
4 x 7 + 4 2804... 537861294 .. Tens > 3200 ... Hunds > All even
5 x 7 + 4 9735... 378612945 .. Tens > 3740 ...
6 x 7 + 4 6... 129453786 .. Tens > 4280 ... Hunds > 3200...
7 x 7 + 4 3597... 861294537 .. Tens > 5720 ...
8 x 7 + 4 0428... 612945378 .. Tens > 6270 ...
9 x 7 + 4 7359... 453786129 .. Tens > 6710 ...
10 x 7 + 4 4280... 294537861 .. Tens > 7251 ...
11 x 7 + 4 1... 945378612 .. Tens > 8701 ... Hunds > 5000 Thous > Even

There is so much here that is fascinating.

I hope that your explorations have gone well!


You may also like

Exploring Wild & Wonderful Number Patterns

EWWNP means Exploring Wild and Wonderful Number Patterns Created by Yourself! Investigate what happens if we create number patterns using some simple rules.

It's All about 64

Write the numbers up to 64 in an interesting way so that the shape they make at the end is interesting, different, more exciting ... than just a square.

Adding All Nine

Make a set of numbers that use all the digits from 1 to 9, once and once only. Add them up. The result is divisible by 9. Add each of the digits in the new number. What is their sum? Now try some other possibilities for yourself!

  • Tech help
  • Accessibility Statement
  • Sign up to our newsletter
  • Twitter X logo

The NRICH Project aims to enrich the mathematical experiences of all learners. To support this aim, members of the NRICH team work in a wide range of capacities, including providing professional development for teachers wishing to embed rich mathematical tasks into everyday classroom practice.

NRICH is part of the family of activities in the Millennium Mathematics Project.

University of Cambridge logo NRICH logo