Hope this helps.

Hope this helps

Thank you Brendan Nkk!

Another possible solution is to do a bit of systematic listing (which is a valid mathematical problem solving heuristic) as follow:

But if you are unlucky,you are likely to be going to guess for a long time.

Brendan Nkk... This is not about lucky or unlucky. Systematic listing is not the same as guess and check. The steps are similar to yours: I used multiple of 35, and if the child cannot "see" why he/she must take the difference (110) and then divide 550 by 110 to get 5, then this systematic listing can help him/her to see the reason behind. Having an additional possible solution provide another way to explain to the child, and help the child see why there is a shorter way to solve the problem, which is your solution.

Thank you Choy Ban Heng !

I'm not keen for students to memorise. They should learn to see the patterns and then form the generalisation.

just an alternative using Triangle Numbers

Cannot.. I think at their level haven't learn yet...

What level is your child in, Karen?

P6

Can do part a.. b n c very hard to explain. .

Can help on this question

Btw thank all for the help

Have to learn to see the pattern at P6. Highly likely to have some pattern questions in PSLE, as it's heuristics. Edlynn Rose's table is helpful, and Kate has a point about a quick formula (but only if the child can grasp the concept behind the formula, because different formulas apply in different situations) During the revision papers that your child will do as prep, urge him to take note and apply his skills for such pattern questions. It's a matter of practice and confidence. Good luck!

Karen Tan. The number of triangle question is not suitable as an item for primary school students. The syllabus does not require students to use "formula" to compute the answer. They are supposed to generalise from the pattern. Furthermore, I have issues with the way the question is phrased. The number of triangles for the first four patterns is strictly not 1, 4, 9 and 16 respectively. This is because, for pattern 2, you can count the whole shape as a triangle, and hence, the answer for pattern 2 could be 5 triangles; likewise for pattern 3, the number of triangles is more than 9 (9 + 4 = 13 to be exact); similarly for pattern 4, the number of triangles is more than 16 because there are "bigger" triangles that can be counted. Maybe you can clarify with the teacher.

Yup... Thank...

For your second question on triangle, note that 1) the area of triangle VXW = area of triangle VXD (same base same height) 2) the area of triangle XYZ = area of triangle XYD (same base same height) 3) the area of triangle VXW + area of triangle XYZ = 1/4 of rectangle ABCD = 25% of rectangle ABCD. Hence, we know that 7% of rectangle ABCD = Area of triangle VXW because area of triangle XYZ = 18%. From here, you should be able to get the answer since 7% of the rectangle ABCD = 154... I will leave it to you to complete the question.

Thank. .. While waiting manage to squeeze out the step n answer.. Very useful.. confirm the answer is right.. we r in the right track...

http://mathworld.wolfram.com/TriangleTiling.html 14a) There are 315 Triangles

XYZ = 18units, total rectangle = 100units. 7units = 154, 1u = 22cm sq. Unshaded area is 75units = 75 x 22 = 1650cm sq

Thank

Are you sure you got the wording right? Are James and MAry walking against the direction the escalator is moving?

if mary takes 45 steps to reach the end while john takes 90... shdn't mary be walking faster?

Anyway, I assumed the wording to "make sense", which means they are walking down the escalator while the escalator was moving down at the same time. If you don't believe it, try it at your nearest mall. let one person take 3 steps for every step taken by the other person. The one who walks faster will reach the other end first, have spend less time on the escalator, and take more steps than the person who walked slower.

The diagram I used is what I use to teach my more advanced P6 students who can deal with Algebra. D=S X T. I used the area of a rectangle to represent distance while the height represents speed and the width represents time, so Area = Height X Width is similar to Dist = Spd X Time. The cross multiplication is tough for Primary kids. Can anyone show a better/simpler method?

Thank you Ben Tang for your detailed answer

ahh... i understand liao. thk u, Ben Tang. :)

Is this a possible solution approach? If my method is correct, it wouldn't require any complicated algebraic formulas.

Good Heuristic, Gabe Lucas!

My pleasure! I love discovering simple visuals to problems like this...