©2012, TESCCC Change Grade 2 Unit 7, Lesson 1

Ripple Effect ©2012, TESCCC

Bicycle ©2012, TESCCC

Communication ©2012, TESCCC

Ancient times In ancient times, people recorded information on clay or wax tablets using sticks. ©2012, TESCCC

Once paper, pens, and inks were invented, people copied books by hand. Most people did not have access to information. ©2012, TESCCC

Printing ©2012, TESCCC

1400 Printing Press In 1439, Gutenberg invented a machine that used movable type. This printing press made information more generally available. ©2012, TESCCC

1714 Typewriter The first typewriter was invented in 1714, but it did not become widely used until the 1800s. Now we use computers to type information. ©2012, TESCCC

1838 Telegraph (and Morse Code) The invention of the telegraph allowed people to send information long distances by using bursts of electricity over wires. ©2012, TESCCC

1896 Telephone Information could be exchanged immediately with the invention of the telephone. ©2012, TESCCC

Telephone ©2012, TESCCC

1927 Television With the invention of television in 1927, visual information could also be shared. ©2012, TESCCC

1940s Computer The first modern computers were invented in the 1940s. They were as big as a room. Now, all sorts of information can be exchanged immediately! ©2012, TESCCC