# Resource Title search

### Half a Minute

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

Anna, Ben and Charlie have been estimating 30 seconds. Who is the best?

### Half a Triangle

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

Construct a line parallel to one side of a triangle so that the triangle is divided into two equal areas.

### Half an Annulus

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

Can you locate the point on an annulus that splits it into two areas?

### Half and Half

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

Two of the four small triangles are to be painted black. In how many ways can this be done?

### Half Area

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

The horizontal red line divides this equilateral triangle into two shapes of equal area. How long is the red line?

### Half Past Two

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

Weekly Problem 21 - 2009
What is the angle between the two hands of a clock at 2.30?

### Half Time

##### Age 5 to 11 Challenge Level:

What could the half time scores have been in these Olympic hockey matches?

### Halfway

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

Can you find a number that is halfway between two fractions?

### Halloween Day

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

One year there were exactly four Tuesdays and four Fridays in October. On what day of the week was Halloween.

### Halloween Investigation

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

Ana and Ross looked in a trunk in the attic. They found old cloaks and gowns, hats and masks. How many possible costumes could they make?

### Hallway Borders

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

What are the possible dimensions of a rectangular hallway if the number of tiles around the perimeter is exactly half the total number of tiles?

### Halving

##### Age 5 to 7 Challenge Level:

These pictures show squares split into halves. Can you find other ways?

### Halving the Triangle

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

Draw any triangle PQR. Find points A, B and C, one on each side of the triangle, such that the area of triangle ABC is a given fraction of the area of triangle PQR.

### Hamilton's Puzzle

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

I start my journey in Rio de Janeiro and visit all the cities as Hamilton described, passing through Canberra before Madrid, and then returning to Rio. What route could I have taken?

### Hamiltonian Cube

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

Weekly Problem 36 - 2007
Find the length along the shortest path passing through certain points on the cube.

### Hampshire CPD Day - March 2015

##### Age 11 to 16

Resources to accompany Charlie's workshops and presentation.

### Hand Span

##### Age 5 to 7 Challenge Level:

Use your hand span to measure the distance around a tree trunk. If you ask a friend to try the same thing, how do the answers compare?

### Hand Swap

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

My train left London between 6 a.m. and 7 a.m. and arrived in Paris between 9 a.m. and 10 a.m. At the start and end of the journey the hands on my watch were in exactly the same positions but the. . . .

### Handling Data

##### Age 5 to 11

This collection of activities covers the areas of probability and collecting and analysing data.

### Handling Data

This collection of resources is designed to help students to improve their understanding of topics in Handling Data.

### Handling Data

This collection of resources is designed to help you to improve your understanding of topics in Handling Data.

### Handling Data (statistics)

These challenges will test your understanding of information, as well as how likely different events are.

### Handling Data (statistics)

##### Age 5 to 7

These challenges will test your understanding of different types of information.

### Handling Data - Short Problems

##### Age 11 to 16

A collection of short Stage 3 and 4 problems on handling data.

### Handling Data KS1

##### Age 5 to 7

These KS1 tasks introduce the skills of collecting data systematically and using it to answer questions.

### Handling Data KS2

##### Age 7 to 11

These KS2 tasks build on the skills of systematically collecting and interpreting data.

### Hands Together

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

Sometime during every hour the minute hand lies directly above the hour hand. At what time between 4 and 5 o'clock does this happen?

### Handshakes

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

Can you find an efficient method to work out how many handshakes there would be if hundreds of people met?

### Handy Angles

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

Weekly Problem 39 - 2008
How big is the angle between the hour hand and the minute hand of a clock at twenty to five?

### Happy Birthday NRICH!

##### Age 7 to 11

To celebrate NRICH's 20th birthday, we have brought together some tasks from NRICH which you might not have come across before. We might call them 'hidden gems'!

### Happy Birthday NRICH!

##### Age 5 to 7

To celebrate NRICH's 20th birthday, we have brought together some tasks from NRICH which you might not have come across before. We might call them 'hidden gems'!

### Happy Halving

##### Age 5 to 7 Challenge Level:

Can you split each of the shapes below in half so that the two parts are exactly the same?

### Happy Octopus

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

This investigation is about happy numbers in the World of the Octopus where all numbers are written in base 8 ... Find all the fixed points and cycles for the happy number sequences in base 8.

### Happy Birthday

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

Can you interpret this algorithm to determine the day on which you were born?

### Haringey 2014-2015

##### Age 5 to 11 Challenge Level:

Find out about the five-term project (January 2014 to July 2015) which NRICH is leading in conjunction with Haringey Council, funded by London Schools Excellence Fund.

### Haringey Leadership for Learning Project 2015-16

##### Age 5 to 11

Find out about the primary maths Leadership project that NRICH is running in Haringey during the academic year 2015-16.

### Harmonic Triangle

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

Can you see how to build a harmonic triangle? Can you work out the next two rows?

### Harmonic Triangles Poster

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

Harmonic Triangles - October 2005

### Harmonically

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

Is it true that a large integer m can be taken such that: 1 + 1/2 + 1/3 + ... +1/m > 100 ?

### Have a Sine

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

There's much more to trigonometry than sin, cos and tan...

### Have You Got It?

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

Can you explain the strategy for winning this game with any target?

### Hawaiian Earring

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

What fraction of the larger circle is outside the smaller circle?