Silverman 
Utilizo máquinas simples [PDF ebook] 
I Use Simple Machines

Head outside and look up. What do you see? At night you might see stars, the moon, the Milky Way, and planets! During the day all these things will still be there, but they’ll be hidden by the bright …

Want to know a secret? Regardless of what classroom challenges, standards or initiatives you’re faced with from year to year, there are seven keys to great teaching that never change—and that are oft …

The ‘Mission Spelling’ series teaches children to spell using phonics, with the help of a lovable little alien, called Zoggy, who has come all the way from planet Zen, three million light years away. …

Have you ever noticed that the physical world works in certain ways? Skateboarders use force and motion to perform tricks. If you jump up as high as you can, you”ll quickly fall back to the ground. …

A kind king in a far off land has been hiding his ears from everyone in his kingdom – even his wife, the queen! He has horse’s ears on his head and he is afraid everyone will laugh if they find out.. …