Q&A - P4 Math

[Nebbermind]

24hr-mum:

is it purely guess n chk?

Since they are facing nos. then the square of the 2 nos. should be on either side of 210.

[AgonyMum]

Need help with these questions!

Other than tedious listing, is there another method/ formula/ short-cut that my child can apply?

1. A book has 2011 pages.How many page numbers are multiples of 3?

2.How many times does the number"1" appear in a book which contains 199 pages? (Again, my same query as Qn 1)

3.How many even-numbered pages are there in a book which has 3055 pages?

4. In a book which contains 100 pages, how many times does the digit "0" appear?

Thanks in advance!

[MathIzzzFun]

AgonyMum:

Need help with these questions!

Other than tedious listing, is there another method/ formula/ short-cut that my child can apply?

1. A book has 2011 pages.How many page numbers are multiples of 3?

2.How many times does the number\"1\" appear in a book which contains 199 pages? (Again, my same query as Qn 1)

3.How many even-numbered pages are there in a book which has 3055 pages?

4. In a book which contains 100 pages, how many times does the digit \"0\" appear?

Thanks in advance!

Hi

Q1. 2011/3 = 670R1 --> 670
...how many multiples of 3 are there from 1 to 10 ?, or how many groups of 3 can we get from a packet of 10 sweets ?



Q2. systematic listing ... but take note of repeating pattern
1-9 --> 1
10-19 --> 11
20-29--> 1
30-99--> 7
100-109 --> same as in 1-10 but now need to add 10 for the 100s, so total 11
similarly, do the same for 110 - 199

Q3. 3055/2 = 1527R1 --> 1527 (same concept as in Q1)

Q4... same concept as in Q2.

cheers.

[24hr-mum]

facing page numbers me consecutive nos

[AgonyMum]

Hi MathIzzzFun

Thank you very much. You are our saviour once again!

[Champion]

Hi! Agonymum,


Sorry to interrupt here; there is an existing thread for P4 Maths Question; perhaps you can post your questions there in the future

http://www.kiasuparents.com/kiasu/forum/viewtopic.php?f=67&t=25121

[AgonyMum]

Duly noted, Champion.

[AgonyMum]

Hi MathIzzzFun, help needed: Thanks in advance!

Excess-Shortage Problems
1. There are some men carrying bicks. If each man carries 4 bricks, there wil be 7 bricks left. If each man carries 5, there will be a shortage of 2 bricks. How many bricks are there?

Can I use : Multiples of 4 (add7) 11,15,19,23,27,31,35,39,43
Multiples of 5(minus2) 3,8,13,18,23,28,33,38,43
When I use this method, I realised that there are 2 answers - 23 and 43.Only 43 seems to be the correct answer. Am I doing something wrong? Is my method correct or is there another more effective method?

2. May walks to school.If she walks at a speed of 60m per minute, she will be late for 5 mins. If she walks at a speed of 75m per min, she will be early for school by 2 mins. What is the distance between her house and her school?

Thanks very much!

[php]

AgonyMum:

Hi MathIzzzFun, help needed: Thanks in advance!

Excess-Shortage Problems
1. There are some men carrying bicks. If each man carries 4 bricks, there wil be 7 bricks left. If each man carries 5, there will be a shortage of 2 bricks. How many bricks are there?

Can I use : Multiples of 4 (add7) 11,15,19,23,27,31,35,39,43
Multiples of 5(minus2) 3,8,13,18,23,28,33,38,43
When I use this method, I realised that there are 2 answers - 23 and 43.Only 43 seems to be the correct answer. Am I doing something wrong? Is my method correct or is there another more effective method?

Thanks very much!

Using Maths Olympiad Method

4 bricks --> +7
5 bricks --> -2

No of men --> (7 + 2) div (5 - 4) = 9

No of bricks --> (9 x 4) + 7 = 43

For checking, (9 x 5) - 2 = 43

[smartmummy]

I think the number of men also should same.u can put the number on the top. Then u can see 43 come in 9th place,23 comes in 4th and th places.so the number of men differ.i guess from previous answers.pls someone assure the method correct?thanks

AgonyMum:

Hi MathIzzzFun, help needed: Thanks in advance!

Excess-Shortage Problems
1. There are some men carrying bicks. If each man carries 4 bricks, there wil be 7 bricks left. If each man carries 5, there will be a shortage of 2 bricks. How many bricks are there?

Can I use : Multiples of 4 (add7) 11,15,19,23,27,31,35,39,43
Multiples of 5(minus2) 3,8,13,18,23,28,33,38,43
When I use this method, I realised that there are 2 answers - 23 and 43.Only 43 seems to be the correct answer. Am I doing something wrong? Is my method correct or is there another more effective method?

2. May walks to school.If she walks at a speed of 60m per minute, she will be late for 5 mins. If she walks at a speed of 75m per min, she will be early for school by 2 mins. What is the distance between her house and her school?

Thanks very much!