Week 4(16th June)

Scratchers:  

This week the Scratchers experimented with random numbers.  In Scratch we can create random numbers using the [pick random {lower num} to {upper num}] block - see figure 1.  This block can be found under the OPERATORS tab

Figure 1:  Random block in scratch found under the OPERATORS tab

Scratcher are excouraged to experiment with using random numbers to add some unpredictability to their programs, as they would find in real games.  For instance, you could move around the screen to random locations as part of a "find and click" game.  Try the block shown in Figure 2 for example.  Note the range I have used for the random numbers.  Refer to week 2 where we discussed how to move around the screen.  In that week we used an x-direction number line (left-right) and a y-direction number line (up-down).  Check to see you understand how large positive and how large negative the x and y number line values can be 

Figure 2: Using random to move around the entire screen

Or maybe you just want your sprite to randomly do one thing or another...like changing costume.  You can use the [if then else]  block we learnt about in week 3.  Try out the code block below (use the cat sprite to ensure you have at least 2 costumes).  The result of this code block is shown in figure 4.

Figure 3:  Random selection of 1 or 2 options (changing costume)

Figure 4:  Result of the random costume changing cat

Gurus:

Figure 5:  Block that results in reflection
of the sprite from each of the 4 walls. 

This week the Gurus helped to take apart an old tower desktop computer.  The students had to identify the hard drive, the memory and the central processing unit (CPU).  Many students made a simple sketch of the motherboard.  If anyone has a sketch they can scan and post from the session, it would be great to see.
Many of the Guru's are having an issue with the return bounce of the ball off the bat or walls in the game of PONG.  This is a reflection-off-a-surface problem.  The ball should come off the wall at the same angle the ball struck the wall.  There is a  detailed block-segment and explanation from the Scratch Wiki, however the math is difficult to appreciate for primary students.  Still the block works fine to use.  Another method uses broadcasts which will not be covered for a few weeks for the Scratchers.  A simpler (maybe) method is shown in the block I created in Figure 5, with the resulting output from this block shown in Figure 6.

Figure 6: Animated sprite reflecting off each
of the 4 walls

From next week 2-3 of the Guru's will be selected each week to help out the Scratchers.  This peer learning is a really effective way for the Scratchers to learn and for the Guru's to improve their own understanding and get recognized for the skills they have already developed. 

Appers:

Network issues are still delaying the Appers from being more productive, but they're in there each week programming away and helping the Guru's develop their skills.  Many thanks to the Appers for their patience and the tech-savvy parents helping to solve the issues.

Old Laptops for Kids

Some parents are interested in using older laptops for their children to experiment with programming and Scratch.  I highly suggest using Puppy (follow the link).  It has a very small installation size so can fit on older laptops/desktops with lower capacity hard drives.  If you're just running a browser and scratch with no intensive video or graphics, this is a simple option for you.