Resources tagged with Common factors similar to HCF Expression:
Other tags that relate to HCF Expression
Logarithmic functions. Factors and multiples. Rational and irrational numbers. Number - generally. Prime factors. Common factors. Combinatorics. Powers & roots. Proof by contradiction. Prime numbers.There are 16 results
Broad Topics > Numbers and the Number System > Common factors
Different by One
Stage: 4 Challenge Level: 
Make a line of green and a line of yellow rods so that the lines differ in length by one (a white rod)
Sieve of Eratosthenes
Stage: 3 Challenge Level:
Follow this recipe for sieving numbers and see what interesting patterns emerge.
Stars
Stage: 3 Challenge Level:
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 hit?
There's Always One Isn't There
Stage: 4 Challenge Level:
Take any pair of numbers, say 9 and 14. Take the larger number, fourteen, and count up in 14s. Then divide each of those values by the 9, and look at the remainders.
Data Chunks
Stage: 4 Challenge Level:
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. . . .
Missing Multipliers
Stage: 3 Challenge Level:
What is the smallest number of answers you need to reveal in order to work out the missing headers?
Counting Cogs
Stage: 2 and 3 Challenge Level:
Which pairs of cogs let the coloured tooth touch every tooth on the other cog? Which pairs do not let this happen? Why?
Inclusion Exclusion
Stage: 3 Challenge Level:
How many integers between 1 and 1200 are NOT multiples of any of the numbers 2, 3 or 5?
Common Divisor
Stage: 4 Challenge Level:
Find the largest integer which divides every member of the following sequence: 1^5-1, 2^5-2, 3^5-3, ... n^5-n.
A First Product Sudoku
Stage: 3 Challenge Level:
Given the products of adjacent cells, can you complete this Sudoku?
Ewa's Eggs
Stage: 3 Challenge Level:
I put eggs into a basket in groups of 7 and noticed that I could easily have divided them into piles of 2, 3, 4, 5 or 6 and always have one left over. How many eggs were in the basket?
Cogs
Stage: 3 Challenge Level:
A and B are two interlocking cogwheels having p teeth and q teeth respectively. One tooth on B is painted red. Find the values of p and q for which the red tooth on B contacts every gap on the. . . .
DOTS Division
Stage: 4 Challenge Level:
Take any pair of two digit numbers x=ab and y=cd where, without loss of generality, ab > cd . Form two 4 digit numbers r=abcd and s=cdab and calculate: {r^2 - s^2} /{x^2 - y^2}.
Hypotenuse Lattice Points
Stage: 4 Challenge Level:
The triangle OMN has vertices on the axes with whole number co-ordinates. How many points with whole number coordinates are there on the hypotenuse MN?
Drawing Celtic Knots
Stage: 3 Challenge Level:
Here is a chance to create some Celtic knots and explore the mathematics behind them.
NRICH is part of the family of activities in the Millennium Mathematics Project.