# Resource Title search

### Rabbit Run

##### Age 7 to 11 Challenge Level:

Ahmed has some wooden planks to use for three sides of a rabbit run against the shed. What quadrilaterals would he be able to make with the planks of different lengths?

### Rabbits in the Pen

##### Age 7 to 11 Challenge Level:

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

### Race Time

##### Age 11 to 14 Short Challenge Level:

Frank and Gabriel competed in a 200m race. Interpret the different units used for their times to work out who won.

### Rachel's Problem

##### Age 14 to 16 Challenge Level:

Is it true that $99^n$ has 2n digits and $999^n$ has 3n digits? Investigate!

### Racing Odds

##### Age 11 to 14 Challenge Level:

In a race the odds are: 2 to 1 against the rhinoceros winning and 3 to 2 against the hippopotamus winning. What are the odds against the elephant winning if the race is fair?

##### Age 11 to 14 Short Challenge Level:

Weekly Problem 41 - 2014
Three straight lines divide an equilateral triangle into seven regions. What is the side length of the original triangle?

### Raffles and Strings

##### Age 16 to 18

How much are you likely to win from a raffle? How many loops will you make with some strings? Here, two guided examples can be found for you to work through.

### Rail Network

##### Age 7 to 11 Challenge Level:

This drawing shows the train track joining the Train Yard to all the stations labelled from A to S. Find a way for a train to call at all the stations and return to the Train Yard.

### Rain

##### Age 11 to 14 Short Challenge Level:

How many dry days did Aisha have on her holiday?

### Rain or Shine

##### Age 16 to 18 Challenge Level:

Predict future weather using the probability that tomorrow is wet given today is wet and the probability that tomorrow is wet given that today is dry.

### Rainstorm Sudoku

##### Age 14 to 16 Challenge Level:

Use the clues about the shaded areas to help solve this sudoku

### Raising the Roof

##### Age 14 to 16 Challenge Level:

How far should the roof overhang to shade windows from the mid-day sun?

### Ramping it Up

##### Age 16 to 18 Challenge Level:

Look at the calculus behind the simple act of a car going over a step.

### Random Inequalities

##### Age 16 to 18 Challenge Level:

Can you build a distribution with the maximum theoretical spread?

### Random Squares

##### Age 16 to 18 Challenge Level:

What is a random pattern?

### Random Variables - Continuous

##### Age 16 to 18

Resources to support an advanced course of statistics

### Random Variables - Discrete

##### Age 16 to 18

Resources to support an advanced course of statistics

### Randomness and Brownian Motion

##### Age 16 to 18

In Classical times the Pythagorean philosophers believed that all things were made up from a specific number of tiny indivisible particles called ‘monads’. Each object contained. . . .

### Rangan's Theory of Cycles

##### Age 14 to 18

In this beautifully written-up investigation Abhay describes his discovery of a 'theory of cycles'.

### Range of Averages

##### Age 11 to 14 Short Challenge Level:

Find these 4 numbers, given their mode, median and range.

### Rarity

##### Age 16 to 18 Challenge Level:

Show that it is rare for a ratio of ratios to be rational.

### Rati-o

##### Age 11 to 14 Challenge Level:

Points P, Q, R and S each divide the sides AB, BC, CD and DA respectively in the ratio of 2 : 1. Join the points. What is the area of the parallelogram PQRS in relation to the original rectangle?

### Ratio and Proportion

The Ratio and Proportion collection of STEM resources

### Ratio and Proportion KS2

##### Age 7 to 11

This collection of activities for KS2 children focuses on ratio and proportion.

### Ratio Cut

##### Age 14 to 16 Short Challenge Level:

Cutting a rectangle from a corner to a point on the opposite side splits its area in the ratio 1:2. What is the ratio of a:b?

### Ratio of Areas

##### Age 14 to 16 Short Challenge Level:

What is the ratio of the area of the hexagon to the area of the triangle?

### Ratio or Proportion?

##### Age 7 to 14

An article for teachers which discusses the differences between ratio and proportion, and invites readers to contribute their own thoughts.

### Ratio Pairs 2

##### Age 7 to 11 Challenge Level:

A card pairing game involving knowledge of simple ratio.

### Ratio Pairs 3

##### Age 11 to 16 Challenge Level:

Match pairs of cards so that they have equivalent ratios.

### Ratio Riddle

##### Age 14 to 16 Short Challenge Level:

Can you work out the ratio b:c given the ratios a:b and a:c?

### Ratio Sudoku 1

##### Age 11 to 16 Challenge Level:

A Sudoku with clues as ratios.

### Ratio Sudoku 2

##### Age 11 to 16 Challenge Level:

A Sudoku with clues as ratios.

### Ratio Sudoku 3

##### Age 11 to 16 Challenge Level:

A Sudoku with clues as ratios or fractions.

### Ratio Swap

##### Age 11 to 14 Short Challenge Level:

How many adults would need to join this group of people to reverse this ratio?

### Ratio, Proportion & Rates of Change

Working on these problems will help your students develop a better understanding of ratio, proportion and rates of change.

### Ratio, Proportion & Rates of Change

Working on these problems will help you develop a better understanding of ratio, proportion and rates of change.

### Ratio, Proportion and Rates of Change - Short Problems

##### Age 11 to 16

A collection of short problems on ratio, proportion and rates of change.

### Rational Integer

##### Age 14 to 16 Short Challenge Level:

Weekly Problem 39 - 2012
For how many values of $n$ are both $n$ and $\frac{n+3}{n−1}$ integers?

### Rational Request

##### Age 16 to 18 Challenge Level:

Can you make a curve to match my friend's requirements?

### Rational Roots

##### Age 16 to 18 Challenge Level:

Given that a, b and c are natural numbers show that if sqrt a+sqrt b is rational then it is a natural number. Extend this to 3 variables.

### Rational Round

##### Age 16 to 18 Challenge Level:

Show that there are infinitely many rational points on the unit circle and no rational points on the circle x^2+y^2=3.

### Rationals Between...

##### Age 14 to 16 Challenge Level:

What fractions can you find between the square roots of 65 and 67?

### Ratios and Dilutions

##### Age 14 to 16 Challenge Level:

Scientists often require solutions which are diluted to a particular concentration. In this problem, you can explore the mathematics of simple dilutions

### Ratty

##### Age 11 to 14 Challenge Level:

If you know the sizes of the angles marked with coloured dots in this diagram which angles can you find by calculation?

### Reach 100

##### Age 7 to 14 Challenge Level:

Choose four different digits from 1-9 and put one in each box so that the resulting four two-digit numbers add to a total of 100.

### Reach for Polydron

##### Age 16 to 18 Challenge Level:

A tetrahedron has two identical equilateral triangles faces, of side length 1 unit. The other two faces are right angled isosceles triangles. Find the exact volume of the tetrahedron.

### Reach for the Stars

##### Age 16 to 18 Challenge Level:

Some graphs grow so quickly you can reach dizzy heights...

### Reaction Rates

##### Age 16 to 18 Challenge Level:

Explore the possibilities for reaction rates versus concentrations with this non-linear differential equation

### Reaction Rates!

##### Age 16 to 18

Fancy learning a bit more about rates of reaction, but don't know where to look? Come inside and find out more...