Download rounding_from_d_to_a

Grade D
Objective : Round to a given number of significant figures (decimals)
Question
a) Work out the value of 3.92 - √75
Write down all the numbers on your calculator display.
(2)
b) Write your answer to part (a) to :
i)
3 significant figures
ii)
2 significant figures
iii)
1 significant figure
Answer
a)
(3)
b) i)
ii)
iii)
Marks
If you get full marks move on to Grade C.
If not ASK FOR HELP………
Extra Question
The number of people at a football match was exactly 83675.
Write this number correct to
i) 3 significant figures
ii) 2 significant figures
iii) 1 significant figure
Answer
i)
ii)
iii)
Now move on to the Grade C questions
(
/ 5 )
Grade C
Objective : Use a calculator efficiently
Round answers to an appropriate degree of accuracy.
Question
a) Use your calculator to work out
Write down all the numbers on your calculator display.
(2)
b) Write your answer to part (a) to an appropriate degree of
accuracy.
Answer
a)
b)
Marks
(
(1)
/ 3 )
If you get full marks move on to the next objective.
If not ASK FOR HELP………
Extra Question
Work out the answer to the following and write down the answer to an
appropriate degree of accuracy.
Answer
Now move on to the next objective………
Grade C
Objective : Recognise the upper and lower bounds of rounded numbers.
Question
A sports commentator reported that 25000 people attended a
snowboarding competition.
The number of people had been rounded to the nearest 1000.
a) Write down the least possible number of people in the
audience. (1)
b) Write down the greatest possible number of people in the
audience. (1)
Answer
a)
b)
Marks
(
/ 2 )
If you get full marks move on to the next objective.
If not ASK FOR HELP………
Extra Question
The distance between two cities is given as 240 miles to the nearest
10 miles.
a) Write down the minimum possible distance between the two cities.
b) Write down the maximum possible distance between the two cities.
Answer
a)
b)
Now move on to the next objective………
Grade C
Objective : Use rounding to make estimates for simple calculations.
Question
Juana walks 17000 every day on average.
She walks approximately 1 mile every 3500 steps.
Work out an estimate for the average number of miles she walks in one
year. (3)
Answer
Marks
If you get full marks try the Grade B objective…
If not ASK FOR HELP………
Extra Question
Builder Bob builds walls, he lays 94 bricks in an hour.
He works for 8 hours for 5 days a week.
How many bricks will he lay in 1 year?
Answer
Now how about a Grade B objective?
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/ 3 )
Grade B
Objective : Calculate upper and lower bounds (involving + and -)
Question
o
The maximum temperature in Salford last year was 25 C to the nearest
o
o
o
C and the minimum temperature was 7 C to the nearest C.
Calculate the range of temperatures.
(3)
Answer
Marks
(
If you get full marks try the Grade A objective…
If not ASK FOR HELP………
Extra Question
Last year Phil was 115cm tall to the nearest cm. This year he was
measured and had grown to 123cm to the nearest cm.
Calculate the range of heights.
Answer
Now how about a Grade A objective?
/ 3 )
Grade A
Objective : Recognise the upper and lower bounds of rounded numbers
(decimals)
Question
5.49 and 12.28 are correct to 2 decimal places.
6.8 is correct to one decimal place.
Which of the following gives the lower bound for x and which gives the
upper bound for x?
A
B
C
D
E
F
Answer
The lower bound is letter ___.
Because
_______________________________________________________
_______________________________________________________
_______________________________________________________
_______________________________________________________
The upper bound is letter ___.
Because
_______________________________________________________
_______________________________________________________
_______________________________________________________
_______________________________________________________
How about trying the next Grade A objective…
Grade A
Objective : Calculate upper and lower bounds (involving x and ÷)
Question
The area of a rectangle, correct to 2 significant figures is 460 cm2.
The length of the rectangle, correct to 2 significant figures is 22 cm.
Writing your answers correct to an appropriate degree of accuracy:
a) Calculate the upper bound for the width of the rectangle
b) Calculate the lower bound for the width of the rectangle
c) Give a reason for your choice of degree of accuracy.
Answer
a)
b)
c)
How about trying a Grade A* objective…
Grade A*
Objective : Select and justify degrees of accuracy for problems involving
compound measures.
Question
The density of kryptonite is 2489 kg/m3.
Writing your answer to an appropriate degree of accuracy, work out:
a) The mass of a piece of kryptonite which has a volume of 2.49 m3
b) The volume of a piece of kryptonite whose mass is 1199kg.
c) Give a reason for your choice of degree of accuracy.
Answer
a)
b)
c)
Now for the last Grade A* objective!
Grade A*
Objective : Calculate the upper and lower bounds of formulae by using
substitution.
Question
The time period, T seconds, of a clock’s pendulum is calculated using the
formula
Where L metres is the length of the pendulum and g m/s2 is the
acceleration due to gravity.
L = 2.36 correct to 2 decimal places.
g = 8.8 correct to 1 decimal place.
a) Find the upper bound of T, giving your answer to 2 decimal places
b) Find the lower bound of T, giving your answer to 2 decimal places
Answer
a)
b)
Yippee!!!