True.
The sun gives the earth thermal energy, which warmth the planet and effects the weather and the seasons. Also the sun is the beginning of the food chain, because it allows for plants to grow.
We also get our energy either directly or in directly from the sun, either from our food that we eat, or through things like the burning of fossil fuels, which was once plant-matter millions of years ago.
It depends ..........................................
Is similar to 3 an you nedd múltiple by 5 and you get 15 for the result
Significant figures let you, and other people looking at your results know how accurate your measurement is.
Hope this helps :)