6B Navigators: Pointers for Mathematics Examinations

WHOLE NUMBERS

Revise order of operations(BODMAS rule) - Brackets first, followed by multiply or divide, whichever comes first, then addition or subtraction, whichever comes first.
Revise 2/3 divided by 1/7. Please invert 1/7 and change the division sign to "multiply".
Revise how to DIVIDE. Example: 17 divided by 3, to 2 dec places = 5.67
1 dec place = one place after decimal
2 dec place = 2 places after decimal
If question did not ask you to round off... PLEASE DO NOT ROUND OFF...
In estimation, rounding off to nearest thousand, look at the hundreds place. More than or equal to 5 then we round up.

TRIANGLES

VOLUME

SPEED

FORMULA = Distance = Speed x Time (Remember the triangle?)
Do not use km/h to multiply by minutes.
Similarly, do not use km/h x metres.
If you really don't understand the question, draw the model the distance to be traveleld.

CONVERSION

1litre = 1000ml
1 kg = 1000g
1m = 100cm
1km = 1000m
5.04 km = 5 km and 40m
6070m = 6.07 km
= 6.07km
Do not make mistakes for conversions. It can affect the whole question's answers. Work with caution and check your work thoroughly.

CIRCLES

Circles questions - Use the "pi" that the question asked you to use. If the question did not state any, use calculator "pi". When using calculator "pi", keep to 3 dec places for working to order to ensure accuracy. Keep to 2 dec places for answers.
FORMULA: Area= "pi" x r x r (r = radius)
: Circumference = "pi" x d (d = diameter)
= 2 x "pi" x r (r = radius)
In finding perimeter of the figure, other than searching for the circumference of the semi-circle, remember to add the sides of the figure.
If you do not know how to find area of a circle, try to dissect the figure.
A circle has 360 degrees, quadrant = 90 degrees and semi-circle = 180 degrees

PERCENTAGE

Gene has 50% more than Yvonne. Therefore, Yvonne should have 100%. Note where the "than" is. Whoever comes after the "then" should be the 100%.
In converting to percentage, for example, 4/5 x 100% = 80% --> You must state the 100%.
Finding percentage increase/decrease = change in quantity divided by original quantity x 100%.
When in face with percentage word problems, remember to convert percentage to fractions. E.g 25% =1/4 etc.
You may want t0 convert to ratio too.

ANGLES

sum of angles on a straight line = 180 degrees
angles in a circle = 360 degrees
sum of angles in between 2 parallel lines = 180 degrees
Rhombus has equal sides, 2 pairs of straight lines and interior angles add up to 180 degrees. It is formed by 2 isoscles triangles.
Parallelogram, 2 pairs of parallelogram. May not be equal in length. Interior angles between a pair of parallel lines add up to 180 degrees.

AVERAGE

ALGEBRA

RATIO

Remember how to form same base.
For instance - they can have the same difference (the question about red and blue pens in Set D- question 46) or the same total.
You can refer to Set D, question 46 and 47 on the ratio questions.

MONEY

PIE CHARTS, LINE GRAPHS

Do revise your pie charts and line graphs. Though the weightage isn't that high, you should know how to do pie charts and line graphs.

NOTES

Remember your word statements
Remember your workings
Remember to transfer your answers to the blanks on the paper.
Remember your units
In answering questions on money, remember to write $26.70 and not $26.7
Revise your square and square roots, cube and cube roots. DO NOT BE CONFUSED BY IT.

Some common questions that you may want to look at...

The questions are not comprehensive... please do your revision... and do not be careless in your working... try your best. :)

Oh... I forgot... BRING CALCULATOR, PROTRACTOR, LONG RULER... SET SQUARE...

REST WELL TONIGHT... JUST REVISE THE FORMULAE and SOME QUESTIONS... KEEP YOUR MIND CALM... GOOD LUCK!

Rgds,
Reginia Loh

6B Navigators