Search by Topic

Resources tagged with Addition & subtraction similar to Become Maths Detectives:

Filter by: Content type:
Stage:
Challenge level: Challenge Level:1 Challenge Level:2 Challenge Level:3

There are 211 results

Broad Topics > Calculations and Numerical Methods > Addition & subtraction

problem icon

Calendar Patterns

Stage: 2 Challenge Level: Challenge Level:1

In this section from a calendar, put a square box around the 1st, 2nd, 8th and 9th. Add all the pairs of numbers. What do you notice about the answers?

problem icon

Street Sequences

Stage: 1 and 2 Challenge Level: Challenge Level:1

Investigate what happens when you add house numbers along a street in different ways.

problem icon

Sometimes We Lose Things

Stage: 2 Challenge Level: Challenge Level:3 Challenge Level:3 Challenge Level:3

Well now, what would happen if we lost all the nines in our number system? Have a go at writing the numbers out in this way and have a look at the multiplications table.

problem icon

Follow the Numbers

Stage: 2 Challenge Level: Challenge Level:1

What happens when you add the digits of a number then multiply the result by 2 and you keep doing this? You could try for different numbers and different rules.

problem icon

It Was 2010!

Stage: 1 and 2 Challenge Level: Challenge Level:1

If the answer's 2010, what could the question be?

problem icon

Sending Cards

Stage: 2 Challenge Level: Challenge Level:1

This challenge asks you to investigate the total number of cards that would be sent if four children send one to all three others. How many would be sent if there were five children? Six?

problem icon

Abundant Numbers

Stage: 2 Challenge Level: Challenge Level:1

48 is called an abundant number because it is less than the sum of its factors (without itself). Can you find some more abundant numbers?

problem icon

Balance of Halves

Stage: 2 Challenge Level: Challenge Level:1

Investigate this balance which is marked in halves. If you had a weight on the left-hand 7, where could you hang two weights on the right to make it balance?

problem icon

Number Squares

Stage: 1 and 2 Challenge Level: Challenge Level:1

Start with four numbers at the corners of a square and put the total of two corners in the middle of that side. Keep going... Can you estimate what the size of the last four numbers will be?

problem icon

Polo Square

Stage: 2 Challenge Level: Challenge Level:1

Arrange eight of the numbers between 1 and 9 in the Polo Square below so that each side adds to the same total.

problem icon

Zargon Glasses

Stage: 2 Challenge Level: Challenge Level:2 Challenge Level:2

Zumf makes spectacles for the residents of the planet Zargon, who have either 3 eyes or 4 eyes. How many lenses will Zumf need to make all the different orders for 9 families?

problem icon

A Square of Numbers

Stage: 2 Challenge Level: Challenge Level:1

Can you put the numbers 1 to 8 into the circles so that the four calculations are correct?

problem icon

Function Machines

Stage: 2 Challenge Level: Challenge Level:2 Challenge Level:2

If the numbers 5, 7 and 4 go into this function machine, what numbers will come out?

problem icon

Rabbits in the Pen

Stage: 2 Challenge Level: Challenge Level:2 Challenge Level:2

Using the statements, can you work out how many of each type of rabbit there are in these pens?

problem icon

Magic Vs

Stage: 2 Challenge Level: Challenge Level:2 Challenge Level:2

Can you put the numbers 1-5 in the V shape so that both 'arms' have the same total?

problem icon

Dart Target

Stage: 2 Challenge Level: Challenge Level:3 Challenge Level:3 Challenge Level:3

This task, written for the National Young Mathematicians' Award 2016, invites you to explore the different combinations of scores that you might get on these dart boards.

problem icon

Mobile Numbers

Stage: 1 and 2 Challenge Level: Challenge Level:1

In this investigation, you are challenged to make mobile phone numbers which are easy to remember. What happens if you make a sequence adding 2 each time?

problem icon

Ladybird Box

Stage: 1 and 2 Challenge Level: Challenge Level:2 Challenge Level:2

Place six toy ladybirds into the box so that there are two ladybirds in every column and every row.

problem icon

Sheep Talk

Stage: 2 Challenge Level: Challenge Level:3 Challenge Level:3 Challenge Level:3

In sheep talk the only letters used are B and A. A sequence of words is formed by following certain rules. What do you notice when you count the letters in each word?

problem icon

The Pied Piper of Hamelin

Stage: 2 Challenge Level: Challenge Level:2 Challenge Level:2

This problem is based on the story of the Pied Piper of Hamelin. Investigate the different numbers of people and rats there could have been if you know how many legs there are altogether!

problem icon

Adding Plus

Stage: 2 Challenge Level: Challenge Level:2 Challenge Level:2

Can you put plus signs in so this is true? 1 2 3 4 5 6 7 8 9 = 99 How many ways can you do it?

problem icon

A-magical Number Maze

Stage: 2 Challenge Level: Challenge Level:2 Challenge Level:2

This magic square has operations written in it, to make it into a maze. Start wherever you like, go through every cell and go out a total of 15!

problem icon

Code Breaker

Stage: 2 Challenge Level: Challenge Level:2 Challenge Level:2

This problem is based on a code using two different prime numbers less than 10. You'll need to multiply them together and shift the alphabet forwards by the result. Can you decipher the code?

problem icon

Open Squares

Stage: 2 Challenge Level: Challenge Level:3 Challenge Level:3 Challenge Level:3

This task, written for the National Young Mathematicians' Award 2016, focuses on 'open squares'. What would the next five open squares look like?

problem icon

Pouring the Punch Drink

Stage: 2 Challenge Level: Challenge Level:3 Challenge Level:3 Challenge Level:3

There are 4 jugs which hold 9 litres, 7 litres, 4 litres and 2 litres. Find a way to pour 9 litres of drink from one jug to another until you are left with exactly 3 litres in three of the jugs.

problem icon

Painting Possibilities

Stage: 2 Challenge Level: Challenge Level:3 Challenge Level:3 Challenge Level:3

This task, written for the National Young Mathematicians' Award 2016, involves open-topped boxes made with interlocking cubes. Explore the number of units of paint that are needed to cover the boxes. . . .

problem icon

Dodecamagic

Stage: 2 Challenge Level: Challenge Level:2 Challenge Level:2

Here you see the front and back views of a dodecahedron. Each vertex has been numbered so that the numbers around each pentagonal face add up to 65. Can you find all the missing numbers?

problem icon

Month Mania

Stage: 1 and 2 Challenge Level: Challenge Level:2 Challenge Level:2

Can you design a new shape for the twenty-eight squares and arrange the numbers in a logical way? What patterns do you notice?

problem icon

Difference

Stage: 2 Challenge Level: Challenge Level:3 Challenge Level:3 Challenge Level:3

Place the numbers 1 to 10 in the circles so that each number is the difference between the two numbers just below it.

problem icon

Arranging the Tables

Stage: 2 Challenge Level: Challenge Level:2 Challenge Level:2

There are 44 people coming to a dinner party. There are 15 square tables that seat 4 people. Find a way to seat the 44 people using all 15 tables, with no empty places.

problem icon

Hubble, Bubble

Stage: 2 Challenge Level: Challenge Level:2 Challenge Level:2

Winifred Wytsh bought a box each of jelly babies, milk jelly bears, yellow jelly bees and jelly belly beans. In how many different ways could she make a jolly jelly feast with 32 legs?

problem icon

On Target

Stage: 2 Challenge Level: Challenge Level:3 Challenge Level:3 Challenge Level:3

You have 5 darts and your target score is 44. How many different ways could you score 44?

problem icon

Prison Cells

Stage: 2 Challenge Level: Challenge Level:2 Challenge Level:2

There are 78 prisoners in a square cell block of twelve cells. The clever prison warder arranged them so there were 25 along each wall of the prison block. How did he do it?

problem icon

Carrying Cards

Stage: 2 Challenge Level: Challenge Level:1

These sixteen children are standing in four lines of four, one behind the other. They are each holding a card with a number on it. Can you work out the missing numbers?

problem icon

Take Three Numbers

Stage: 2 Challenge Level: Challenge Level:1

What happens when you add three numbers together? Will your answer be odd or even? How do you know?

problem icon

Dotty Six

Stage: 1 and 2 Challenge Level: Challenge Level:1

Dotty Six is a simple dice game that you can adapt in many ways.

problem icon

Sorting the Numbers

Stage: 1 and 2 Challenge Level: Challenge Level:1

Complete these two jigsaws then put one on top of the other. What happens when you add the 'touching' numbers? What happens when you change the position of the jigsaws?

problem icon

X Is 5 Squares

Stage: 2 Challenge Level: Challenge Level:2 Challenge Level:2

Can you arrange 5 different digits (from 0 - 9) in the cross in the way described?

problem icon

Magic Constants

Stage: 2 Challenge Level: Challenge Level:2 Challenge Level:2

In a Magic Square all the rows, columns and diagonals add to the 'Magic Constant'. How would you change the magic constant of this square?

problem icon

Exploring Wild & Wonderful Number Patterns

Stage: 2 Challenge Level: Challenge Level:1

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

problem icon

Strike it Out for Two

Stage: 1 and 2 Challenge Level: Challenge Level:1

Strike it Out game for an adult and child. Can you stop your partner from being able to go?

problem icon

Dotty Six for Two

Stage: 1 and 2 Challenge Level: Challenge Level:1

Dotty Six game for an adult and child. Will you be the first to have three sixes in a straight line?

problem icon

Two Egg Timers

Stage: 2 Challenge Level: Challenge Level:2 Challenge Level:2

You have two egg timers. One takes 4 minutes exactly to empty and the other takes 7 minutes. What times in whole minutes can you measure and how?

problem icon

How Old?

Stage: 2 Challenge Level: Challenge Level:2 Challenge Level:2

Cherri, Saxon, Mel and Paul are friends. They are all different ages. Can you find out the age of each friend using the information?

problem icon

Next Number

Stage: 2 Short Challenge Level: Challenge Level:2 Challenge Level:2

Find the next number in this pattern: 3, 7, 19, 55 ...

problem icon

Being Resilient - Primary Number

Stage: 1 and 2 Challenge Level: Challenge Level:1

Number problems at primary level that may require resilience.

problem icon

Machines

Stage: 2 Challenge Level: Challenge Level:1

What is happening at each box in these machines?

problem icon

A Mixed-up Clock

Stage: 2 Challenge Level: Challenge Level:1

There is a clock-face where the numbers have become all mixed up. Can you find out where all the numbers have got to from these ten statements?

problem icon

Rod Measures

Stage: 2 Challenge Level: Challenge Level:3 Challenge Level:3 Challenge Level:3

Using 3 rods of integer lengths, none longer than 10 units and not using any rod more than once, you can measure all the lengths in whole units from 1 to 10 units. How many ways can you do this?

problem icon

The Dice Train

Stage: 2 Challenge Level: Challenge Level:3 Challenge Level:3 Challenge Level:3

This dice train has been made using specific rules. How many different trains can you make?


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. More information on many of our other activities can be found here.
Copyright © 1997 - 2018. University of Cambridge. All rights reserved.
NRICH is part of the family of activities in the Millennium Mathematics Project.