# Resource Title search

### Daisy

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

A game for 2 players. Draw a daisy with at least 5 petals. Shade 1 or 2 petals next to each other. The winner shades the last petal.

### Dalmatians

##### Age 14 to 18 Challenge Level:

Investigate the sequences obtained by starting with any positive 2 digit number (10a+b) and repeatedly using the rule 10a+b maps to 10b-a to get the next number in the sequence.

### Dam Busters 1

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

At what positions and speeds can the bomb be dropped to destroy the dam?

### Dam Busters 2

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

Can you work out which of the equations models a bouncing bomb? Will you be able to hit the target?

### Dancing with Maths

##### Age 7 to 16

An article for students and teachers on symmetry and square dancing. What do the symmetries of the square have to do with a dos-e-dos or a swing? Find out more?

### Dangerous Driver?

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

Was it possible that this dangerous driving penalty was issued in error?

### Daniel's Star

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

A solid 'star' shape is created. How many faces does it have?

### Dart Target

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

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.

### Darts and Kites

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

Explore the geometry of these dart and kite shapes!

### Data and Statistics

##### Age 11 to 18 Challenge Level:

These problems are designed to help Stage 3, 4 and 5 students to handle data and work with statistics.

### Data Chunks

##### Age 14 to 16 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. . . .

### Data Handling

The Data Handling collection of STEM resources

### Data Matching

##### Age 14 to 18 Challenge Level:

Use your skill and judgement to match the sets of random data.

### Data Shapes

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

Sara and Will were sorting some pictures of shapes on cards. "I'll collect the circles," said Sara. "I'll take the red ones," answered Will. Can you see any cards they would both want?

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

If a sum invested gains 10% each year how long before it has doubled its value?

### David and Goliath

##### Age 14 to 18 Challenge Level:

Does weight confer an advantage to shot putters?

### Day of the Triffids

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

Jasmine buys three different types of plant. How many triffids did she buy?

### Day Out

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

Chris cycled faster than expected. Can you work out his average speed?

### Days and Dates

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

Investigate how you can work out what day of the week your birthday will be on next year, and the year after...

### Dean's Mountain

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

Dean runs down the mountain at 12 km per hour. How long does it take him to run down the mountain?

### Debasing the Coinage

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

How much lighter will £5 worth of 5p's be with these new lighter coins?

### Debt Race

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

Who will be the first investor to pay off their debt?

### Debt Recovery

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

Tony and Tina can't work out which of them owes what to the other. Can you?

### Decathlon: the Art of Scoring Points

##### Age 14 to 18

How do decisions about scoring affect who wins a combined event such as the decathlon?

### Decimal Clock

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

A decimal clock is started at midnight. What time would it show at 6 o'clock in the morning?

### Decimal Time

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

Use the clocks to investigate French decimal time in this problem. Can you see how this time system worked?

### Decimal Time Poster

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

Decimal Time - March 2006

### Decision Curriculum Mapping

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

The A-level Decision Curriculum Mapping Pages

### Decision Resources

##### Age 16 to 18

A selection of resources suitable for A-level Decision mathematics

### Decoding Transformations

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

See the effects of some combined transformations on a shape. Can you describe what the individual transformations do?

### Deep Roots

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

Find integer solutions to: $\sqrt{a+b\sqrt{x}} + \sqrt{c+d.\sqrt{x}}=1$

### Defined Distances

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

Mark writes four points on a line at different lengths. What is the distance between the two points furthest apart?

### Degree Ceremony

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

What does Pythagoras' Theorem tell you about these angles: 90°, (45+x)° and (45-x)° in a triangle?

### Delia's Routes

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

A little mouse called Delia lives in a hole in the bottom of a tree.....How many days will it be before Delia has to take the same route again?

### Descending Angles

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

Given four of the angles in two triangles, can you find the smallest angle overall?

### Descending Deal

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

Four cards from a set numbered 1-36 are dealt. What is the probability that they are dealt in order?

### Design

The Design collection of STEM resources

### Design Technology

##### Age 11 to 16

The Design Technology collection of STEM resources.

### Design Technology - Classroom Problems

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

A list of stemNRICH Living World problems with teacher support notes.

### Designer Maths

##### Age 11 to 16

Design is mathematical! Find out more with these resources.

### Designing a Polynomial

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

Can you find a polynomial function whose first derivative is equal to the function?

### Designing Table Mats

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

Formulate and investigate a simple mathematical model for the design of a table mat.

### Developing a Framework for Mathematical Enrichment

This paper considers the key aspects of mathematics enrichment and how the content and design of trails (as well as the NRICH site itself) has been influenced by, and built upon, these philosophies.

### Developing Able Young Mathematicians

##### Age 5 to 11

These activities are particularly good for challenging high-attaining primary children.

### Developing Excellence in Problem Solving with Young Learners

##### Age 5 to 11

Becoming confident and competent as a problem solver is a complex process that requires a range of skills and experience. In this article, Jennie suggests that we can support this process in three. . . .