Modual 10 Flashcards
How can proportion’s be written?
as a fraction: a c
- = -
b d
as a colon- a:b = c:d
a:b = c:d can also be expressed in multiplying. How would this be written?
a x d = b x c
3/5 can also be written as?
12/35
What is cross product?
It’s like cross cancel
write 20/25 = 4/5 as a cross product
20 x 5 = 25 x 4
100 = 100
How do you work out the missing term in proportion? e.g. 20/59 = 30/x
STEP 1: write the proportion
STEP 2: cross product e.g. 20 X x = 50 X 30
STEP 3: divide both sides e.g. divide by 20 = x = 75
What is a conversion factor? e.g. what is the CF of 2.55 and £1 = $1.5
the most logical number
e. g. CF = 60 minutes (how many minutes in an hour)
e. g. CF = $1.5 (exchange rate)
Convert 2.55 hours into minutes
CF =
- 55hours x 60 =153 min
- 55hours / 60 = 0.042 min
= 153 minutes
What do you have to do in a conversion factor question?
you have to / and x the original number by the conversion factor and pick the most logical answear
Metric Units: length
mm, cm, m, km
Metric Units: area
mm{squared}, cm{squared}, m{squared}, km{squared}
Metric Units: volume
mm{cubed}, cm{cubed}, m{cubed}, litres, ml
Metric Units: weight
g, kg, tonnes
Metric Units: speed
km/h, m/s
Imperial Units: length
inches, feet, yards, miles
Imperial Units: area
square inches, square feet, square yard, square mile
Imperial Units: v olume
cubic inches, cubic feet, gallons, pints
Imperial Units: weight
ounces, pounds, stone, tones
Imperial Units: sped
mph
1cm =…mm
= 10mm
1km=…cm
= 100cm
1km=….m
= 1000m
1kg=….g
= 1000g
1 tonne=….kg
= 1000kg
1 litre=…..cm{cubed}
= 1000cm{cubed}
1cm{cubed}=..ml
= 1ml
1 foot=…inches
= 12 inches
1 yard=.. foot
= 3 foot
1 gallon=… pints
= 8 pints
1 stone=… pounds
= 14 pounds
1 pounds =… ounches
= 16 ounches
Speed x time =
distance
distance / speed =
time
distance / time =
speed
density x volume =
mass
mass / density =
volume
mass / volume =
density
What does direct proportion mean?
both increase togther
Direct proportion: In a table of x and y, the top number and the bottom number do what?
get x by the same number
e.g. if you x the top number by 3 you have to x the number underneath that number by 3
What is the formula for Direct Proportion?
y = kx
What does inverse proportion mean?
If one increase, the other will decrease
Inverse proportion: in a table of x and y, what does the top number and the bottom number do?
The top number x and the bottom number /
e.g. if you x the top number by 2, the number underneath, you would / by 2
What is the formula for Inverse Proportion?
y = k/x
What does proportion mean?
two ratios that are equal
A pack of 6 balls cost £45. How much would 4 cost?
£45 / 6 = £7.5
£7.5 x 4 = £30
What can map scales tell you?
how many units of land are equal to 1 unit on the map
What does the scale of 1: 100 00 mean?
that the real distance is 100 00 times the length of 1 unit on the map
Write the scale of 1cm to 1m in ratio form
1cm : 1m
1cm : 100m
1 : 100
