### Fibs

The well known Fibonacci sequence is 1 ,1, 2, 3, 5, 8, 13, 21.... How many Fibonacci sequences can you find containing the number 196 as one of the terms?

### Helen's Conjecture

Helen made the conjecture that "every multiple of six has more factors than the two numbers either side of it". Is this conjecture true?

### First Forward Into Logo 10: Count up - Count Down

What happens when a procedure calls itself?

# First Forward Into Logo 1: Square Five

##### Age 7 to 16Challenge Level

First Forward Into Logo

This is the first in a twelve part series of articles introducing Logo programming for beginners. Even if you have never tried LOGO it is easy to learn and here is the place to get started! The programs in this article were written using MSWLogo and you can download this excellent free software from the internet at http://fmslogo.sourceforge.net/.

With only a limited set of instructions (i.e. primitives) it is usually quite straightforward to draw the most complex of shapes on the screen or to get the turtle' to manoeuvre about the floor.

For example, using instructions such as:

forward 40 (FD 40)
or
backward 20 (BK 20),
right 85 (RT 85 )
or
left 125 (LT 125)



The difficulty always seems to be about remembering to put spaces between the commands - FD, BK, RT, or LT and the amount of distance or turning you want the screen or floor turtle to achieve:

 e.g. FD 70 RT 90 FD 130 RT 90 FD 70 RT 90 FD 130 RT 90  
And, there is the convention of returning the screen or floor turtle to exactly the same place that it had started from.

The NRICH site has a number of LOGO Challenges for you to think about and respond to. In many cases you will know how well you are doing by how quickly you manage to copy the drawing exactly, in others the aim is for you to investigate the code you have been given and discover what is going on.

When you work at the problems it would be helpful to keep a simple diary of what you were thinking at the time and what you learnt while trying to respond to the challenges set. What mathematics did you learn along the way? Are you getting better at learning things independently? What did you learn about yourself?

e.g.
• How impatient did you become?
• How did you get round the difficulties you met?
• Did you share what you did with others?
• Did other people help you solve the challenge? In what ways?
• What happened when the instructions you had worked out did not draw the shape required?

##### The first LOGO Challenge

For now, a reminder of some of the PRIMITIVES (the commands) needed to start drawing:

FD forward        BK backward

LT left           RT right

PU pen up         PD pen down

HT hide turtle    ST show turtle

CS clear screen   CT clear text

Now FD to the first challenge...
`

Can you use LOGO to draw the 5-square?

Next: FF2