**Mathematics 3** ESO – Unit 1 REAL NUMBERS page 11 activity 58

**1 –** Complete with the word “factor/multiple”:

- a) 5 is a ___________ of 35
- b) 16 is a ___________ of 2

- c) 105 is a ___________ of 3

- d) 6 is a ___________ of 54

- e) 10 is a ___________ of 100

- f) 100 is a ___________ of 10

**2 –** Watch the video on “Standard index form” and answer:

- a) What did Archimedes calculate?
- b) Who came up with a good way to write numbers that are really big or really small? How did he call it?
- c) Can the number before that multiplies the power be 10? Can it be greater than 10?
- d) When is the exponent positive? And when is it negative?
- e) How do we find the value of the exponent in very large numbers?
- f) How do we find the value of the exponent in very small numbers?
- g) When doing calculations with Standard form, what rules do we use?
- h) If when multiplying the numbers before the exponents we get a number equal or greater than 10… What do we do?
- i) Solve:
- I) 3.2ˑ10
^{3}ˑ 6.5ˑ10^{6} - II) 4.79ˑ10
^{-3}ˑ 5.2ˑ10^{-9} - III) 1.12ˑ10
^{-3}ˑ 4.8ˑ10^{7}

- I) 3.2ˑ10