If you have a packet of seeds you will probably find instructions on the packet to water the seeds. What would happen if you did not water them?
Problem to solve: Do seeds need water in order to grow?
Prediction: You think they do!
Now do a fair test to see if you are right.
TEST
First of all you could guess what might happen.
Then you could do a test to find out.
To answer the second question you could take two trays, and put some earth and seeds in each. The test must be fair. This means that you must keep everything the same (like the amount of soil and number of seeds and the place you put them) except for the thing that you are testing (watering). You could water one tray every few days, but not the other. Then you compare the two trays after a week or two. Do you notice any difference?
Scientists usually write down what they find, and they often count or measure things as well. They often make charts, like this:
| AFTER HOW MANY DAYS | NUMBER OF SEEDLINGS IN TRAY 1 | NUMBER OF SEEDLINGS IN TRAY 2 |
| 3 | 0 | 0 |
| 6 | 0 | 1 |
| 9 | 0 | 4 |
| 12 | 0 | 8 |
Look at your chart. Did the test show that your idea was right?
What else could you discover about what seeds need in order to grow.
Do they need light?
Can you think up a fair test to answer this question?
In this way scientists build up a lot of knowledge about lots of things.
But tests do not always work out the way you think they might. And scientists can often be wrong! (The early scientists thought that the Earth was flat! And they also thought that the sun moved around the Earth!)