Lesson 16.4: Science Connection

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What time is it? Check your watch. Now check other watches or clocks. Do they all show the same hour? Do they all show the same number of minutes?

You can set your watches and clocks to show exactly the same time. Check them a few days later. Do they still show exactly the same time? Some of them may work too quickly. These gain time. Others may work too slowly. These lose time.

Atomic clocks keep time better than any other clocks. An atomic clock loses less than 1 second of time in 1 million years! Atomic clocks help everyone in the world measure the time of day in the same way. Without atomic clocks, the Internet would not work well because computers in different places would be set to different times.

Word Wise

Amount of time equal to 60 minutes: I took one hour to do my homework.

Amount of time equal to 60 seconds: I can tie my shoes in one minute.

Network that links computers all over the world: I need to click two times to get to the Internet.

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You know what the words hour and our mean. These two words sound alike. But they are not spelled alike and they mean different things. These words are called homophones.

Say each pair of homophones below. Copy them on a sheet of paper. Then write a sentence using each word. You may use a dictionary if you don't know the meaning of any word.

  1. hour: blank
    our:   blank
  2. mail:   blank
    male: blank
  3. deer: blank
    dear: blank

Data Hunt

What Time Is It? Quiz
Can you tell time? Take the What Time Is It? Quiz to find out.