Things to note for Topics for Semester 2:
1) Ratio
The
children commented that Ratio is like doing P3 work and I reminded them not to
get complacent and make unnecessary mistakes.
· Order
is important when writing ratio so your child must read carefully
before writing the final ratio as their answer.
· When
writing ratio as the final answer, they need to make sure that there is no
units, fraction and decimals written.
· As
they felt that ratio is a relatively easy topic and the numbers are manageable, all equations must be shown as evidence of
their thinking processes.
2) Average
· If
any two of these information are given (Average, total number of data or Sum of
data), they will be able to find the third information. Normally they are able
to solve such questions easily.
· They
just need to be careful whether the data given is referring to the average of
the items or the sum of items.
· Average
does not represent the actual number in each group. It is the best
estimate of the number of items in each group have.
· Most
of them will have problems with the evening out process to find the average. For such questions, I reminded them to do their checking
based on the final answers to make sure that they have answered the questions
correctly.
3) Percentage
· %
is not a standard unit. When added to a number, it will change the value of the
number. Thus they have to be careful where they put % as it may result in the
deduction of half a mark due to the wrong use of equal sign. For example: They
write 48/240 x 100% = 480/24 = 20% instead of 48/240
x 100% = (480/24)% = 20% . They write $20 x 22 % = $440 instead
of $20 x 22 = $440.
· When
converting percentage to decimal or fraction, they need to remember that
percent means every 100 which mean 26.2% = 26.2/100. Then they need
to multiply by 5 to get rid of the decimal so that the final answer is truly a
fraction (131/500).
· For
GST, they have to remember that it is charged on the discounted price and not
on the discount or original price. They will always need to work out what the
price is after the discount before they can find GST.
4) Angles, Triangles and
Four-sided Figures
· It
is important that they either identify which angles they are referring to using
the letters given or label the angles in the diagrams. If they did not identify
or label, marks will not be awarded as the teacher will not know which angles
they are referring to.
· They
cannot assume the lines are straight unless stated in the question.
· For
isosceles triangles, they need to remember to label the two equal angles before
finding the third angle.
· Construction
must be done in pencil. All the information given in the question must be
labelled in the figure that they draw. Marks will be deducted for missing
information. There are always hidden information that they must know so that
they can construct the shape accurately. Thus it is important to revise the
properties of the four-sided figures and the triangles so that their
construction is accurate.
Please remember to bring along your calculator and mathematical instrument set. =)
