Jason Khng
Asked 9 years ago

SG chevron_right Primary 5 chevron_right Number and Algebra

Replies 3
Xavier Sng

(a) 100 min before 1 pm is 11.20am. (b) Speed of slower machine = (70 × 6) ÷ (100 - 70) = 14 copies a minute. Total copies printed by both machines = 14 × 100 × 2 = 2800

6 years ago
Jason Khng

Thank you very much

6 years ago
Xavier Sng

The pleasure is mine. Regards

6 years ago

Jason Oon
Asked 9 years ago

SG chevron_right Primary 5 chevron_right Number and Algebra

P5 Question. Can I do by even easier method so a P5 student can apply? Thanks. I can do by highest common factor, orby listing the factors of the smaller number, 36, and divide 90 by the number to get whole number for the answer.Ans: 18P.S. Credits to Raymond & Xavier.

Replies 4
Raymond Ng

6 years ago
Jason Oon

This is better, thanks Raymond

6 years ago
Xavier Sng

Good morning Jason. P5 students should easily recognise that 36 and 90 are multiples of 9.

6 years ago
Xavier Sng

As such they can infer that 36 = 9 × 4 = 18 × 2 90 = 9 × 10 = 18 × 5, it is easy to see that 18 groups of 2 boys and 5 girls can be formed.

6 years ago

Adrian Ng
Asked 9 years ago

SG chevron_right Primary 6 chevron_right Fractions

Making it visual...

Replies 3
Cyn Puan

Hi may I knw which level is this?

6 years ago
Adrian Ng

P5/P6

6 years ago
Cyn Puan

Oh ok thanks phew.... I thot p3.... But good to learn in advance. Thanks

6 years ago

Jason Oon
Asked 9 years ago

SG chevron_right Primary 5 chevron_right Measurement

P5 question. Updated with solution. As mentioned by Raymond below, using simple symmetry:Since the diagonal line AE cuts the entire rectangle into two halves, ABXH & XDEF are already bisected nicely, therefore the remaining two rectangles must have the same area. Hence, shaded area = 12 x 3 = 36 cm2Alternatively by ratio, BX : DE, 9 : 3 --> 3 : 1 such thatAB : XD, 12 : 4Hence, area of shaded part = 4 x 9 = 36 cm2

Replies 9
Xavier Sng

You are correct, Sir.

6 years ago
Jason Oon

Thanks Xavier

6 years ago
Xavier Sng

Thank you, Jason.

6 years ago
Chia-Chan Bk

Another method.

6 years ago
Raymond Ng

Jason Oon, in my opinion, I think Chia-Chan Bk method is more appropriate for Pri Sch. By using ratio, you may have inadvertently adopted the Intercept Theorem, similar triangles which are introduced in Sec Sch.

6 years ago
Jason Oon

I see. Any idea what method did Chia-Chan Bk use?

6 years ago
Raymond Ng

Simple symmetry ☺

6 years ago
Raymond Ng

The 2 rectangles have the same area.

6 years ago
Raymond Ng

Diagonal AE cuts the entire rectangle into two halves. Since ABXH & XDEF are already bisected nicely, the remaining two rectangles must have the same area.

6 years ago

Irene Ong
Asked 9 years ago

SG chevron_right Primary 6 chevron_right Number and Algebra

Replies 1
Xavier Sng

6 years ago

About

Students

Tutors