scientific notation and significant figure

write 320 000 000 in scientific notation

= 3.2 x 100 000 000

= 3.2 x 10^8

Write 7.1 x 10^-5 as a decimal

= 7.1 / 10^5

= 0.000 0 71

Round the number to significant figure in brackets. 4 592 170 (3 s.f)

For 3 s.f, look at 4th digit, 0-4 round down.

= 4 590 000

0.248 391 (2 s.f), 3rd non zero digit 5-9 round up.

= 0.25

1.396 794 ( 3 s.f), 4th digit 5-9 round up 39>40)

= 1.40

scientific notation

- used for very large or small numbers

- is written as a number between 1 and 10 multiplied by the power of 10