Number

Question 1

How can you tell if a fraction produces a terminating decimal?

Answer 1

Write the denominator as a product of its prime factors - if the prime factors are ONLY 2 and 5, it’s terminating.

Question 2

How can you tell if a fraction produces a recurring decimal?

Answer 2

Write the denominator as a product of its prime factors - if it has prime factors other than 2 and 5, it’s recurring.

Question 3

When estimating, you round to…

Answer 3

1 significant figure, e.g. 4.32 x 18.09 = 4 x 20 = 80

Question 4

What is the rule when converting recurring decimals into fractions?

Answer 4

Multiply by...
     10 if 1 digit recurs
     100 if 2 digits recur
     1000 if 3 digits recur
       etc..

Question 5

What are the rules for finding the overall upper bounds in calculations?

Answer 5

UB + UB
UB - LB
UB x UB
UB / LB

Question 6

What are the rules for finding the overall lower bounds in calculations?

Answer 6

LB + LB
LB - UB
LB x LB
LB / UB

Question 7

How do you calculate an answer to an appropriate degree of accuracy when considering bounds?

Answer 7

Calculate the upper and lower bounds, then work back from the last value until both answers round down/up to the same number.
e.g.
If UB = 5.13469 and the LB = 5.12984 then the answer would be 5.1 because after 2 sig. fig. the answers disagree.

Question 8

Product rule for counting?

Answer 8

see separate stack