Find the largest integer which divides every member of the
following sequence: 1^5-1, 2^5-2, 3^5-3, ... n^5-n.
Find a cuboid (with edges of integer values) that has a surface
area of exactly 100 square units. Is there more than one? Can you
find them all?
The clues for this Sudoku are the product of the numbers in adjacent squares.
Can you convince me of each of the following: If a square number is
multiplied by a square number the product is ALWAYS a square
115^2 = (110 x 120) + 25, that is 13225 895^2 = (890 x 900) + 25, that is 801025 Can you explain what is happening and generalise?
Some 4 digit numbers can be written as the product of a 3 digit
number and a 2 digit number using the digits 1 to 9 each once and
only once. The number 4396 can be written as just such a product.
Can. . . .
A game that tests your understanding of remainders.
Can you find a way to identify times tables after they have been shifted up?
Find the frequency distribution for ordinary English, and use it to help you crack the code.
What is the smallest number of answers you need to reveal in order
to work out the missing headers?
Here is a machine with four coloured lights. Can you develop a strategy to work out the rules controlling each light?
Explore the relationship between simple linear functions and their
Do you know a quick way to check if a number is a multiple of two? How about three, four or six?
Given any 3 digit number you can use the given digits and name another number which is divisible by 37 (e.g. given 628 you say 628371 is divisible by 37 because you know that 6+3 = 2+7 = 8+1 = 9). . . .
Prove that if the integer n is divisible by 4 then it can be written as the difference of two squares.
Find the smallest positive integer N such that N/2 is a perfect
cube, N/3 is a perfect fifth power and N/5 is a perfect seventh
The nth term of a sequence is given by the formula n^3 + 11n . Find
the first four terms of the sequence given by this formula and the
first term of the sequence which is bigger than one million. . . .
A challenge that requires you to apply your knowledge of the
properties of numbers. Can you fill all the squares on the board?
Factorial one hundred (written 100!) has 24 noughts when written in full and that 1000! has 249 noughts? Convince yourself that the above is true. Perhaps your methodology will help you find the. . . .
A game in which players take it in turns to choose a number. Can you block your opponent?
Have you seen this way of doing multiplication ?
Caroline and James pick sets of five numbers. Charlie chooses three of them that add together to make a multiple of three. Can they stop him?
Make a line of green and a line of yellow rods so that the lines
differ in length by one (a white rod)
Play the divisibility game to create numbers in which the first two digits make a number divisible by 2, the first three digits make a number divisible by 3...
You are given the Lowest Common Multiples of sets of digits. Find
the digits and then solve the Sudoku.
Data is sent in chunks of two different sizes - a yellow chunk has
5 characters and a blue chunk has 9 characters. A data slot of size
31 cannot be exactly filled with a combination of yellow and. . . .
List any 3 numbers. It is always possible to find a subset of
adjacent numbers that add up to a multiple of 3. Can you explain
why and prove it?
Prove that if a^2+b^2 is a multiple of 3 then both a and b are multiples of 3.
Imagine we have four bags containing numbers from a sequence. What numbers can we make now?
What is the largest number which, when divided into 1905, 2587,
3951, 7020 and 8725 in turn, leaves the same remainder each time?
Can you work out what size grid you need to read our secret message?
Can you find a relationship between the number of dots on the
circle and the number of steps that will ensure that all points are
This article takes the reader through divisibility tests and how they work. An article to read with pencil and paper to hand.
Helen made the conjecture that "every multiple of six has more
factors than the two numbers either side of it". Is this conjecture
A collection of resources to support work on Factors and Multiples at Secondary level.
What is the smallest number with exactly 14 divisors?
A game for two people, or play online. Given a target number, say 23, and a range of numbers to choose from, say 1-4, players take it in turns to add to the running total to hit their target.
The number 8888...88M9999...99 is divisible by 7 and it starts with
the digit 8 repeated 50 times and ends with the digit 9 repeated 50
times. What is the value of the digit M?
Find some triples of whole numbers a, b and c such that a^2 + b^2 + c^2 is a multiple of 4. Is it necessarily the case that a, b and c must all be even? If so, can you explain why?
The number 12 = 2^2 × 3 has 6 factors. What is the smallest natural number with exactly 36 factors?
How many integers between 1 and 1200 are NOT multiples of any of
the numbers 2, 3 or 5?
Each letter represents a different positive digit
AHHAAH / JOKE = HA
What are the values of each of the letters?
Can you find any perfect numbers? Read this article to find out more...
Find the highest power of 11 that will divide into 1000! exactly.
The puzzle can be solved by finding the values of the unknown digits (all indicated by asterisks) in the squares of the $9\times9$ grid.
Imagine we have four bags containing a large number of 1s, 4s, 7s and 10s. What numbers can we make?
Factor track is not a race but a game of skill. The idea is to go round the track in as few moves as possible, keeping to the rules.
Follow this recipe for sieving numbers and see what interesting patterns emerge.
Substitution and Transposition all in one! How fiendish can these codes get?
For this challenge, you'll need to play Got It! Can you explain the strategy for winning this game with any target?