## Did you see rubbish on your way to school today?

Wouldn’t it be great to organise a day of tidying up? It’s a big job, so you’re going to need some rubbish grabbers.

How can you find the best grabber for the job?

## Build two grabbers.

You’ll start by testing these 2 grabbers. You’ll also need a controller.

If you have enough time, you should build and test your own design.

## Gather the ‘rubbish’.

You’ll need :

• 1 LEGO brick
• 1 empty plastic bottle
• 1 ball of crumpled paper
• 1 stack of LEGO wheels
• 1 apple (or any round fruit)

You can replace the apple with any object of the same size and weight.

## Play this program to test the 2 grabbers.

Which one do you think works the best?

## Test #1: Object Size

Try to use each grabber to pick up the empty bottle, crumpled paper and LEGO brick.

Give it a score:

• 1 point if it grabs, lifts and moves the object
• 0 points if it grabs but drops the object
• -1 point if it doesn’t grab or lift the object

Note your scores in a table.

## Test #2: Object Weight

Repeat the last test using the LEGO wheels, crumpled paper and an apple.

Note your scores in another table.