Recurring decimals Flashcards
1
Q
How do you convert a recurring decimal into a fraction?
A
1) write the recurring decimal as n
2) multiply by 10/100/1000
3) subtract to remove the recurring part
4) divide by 9, 99, or 999 to write as a fraction
2
Q
What do you multiply by if:
1) 1 digit recurs
2) 2 digits recur
3) 3 digits recur
A
1) 10
2) 100
3) 1000
3
Q
Prove that the recurring decimal 0.24 has the value 8/33
A
n = 0.24242424…
100n = 24.24242424…
n = 0.24242424
99n = 24
n = 24/99 = 8/33
4
Q
Show that 0.473 (4 doesn’t recur) can be written as 469/990
A
n = 0.47373737
(STILL ONLY X BY 100!)
100n = 47.37373737
n = 0.47373737
99n = 46.9
n = 46.9/99
n = 469/990