Tutor MathsGuru: Ask me for your burning Maths questions!

[MathIzzzFun]

starry15:

MathizzFun,

My mistake. It should be :

Miss Lim bought a packet of sweets to distribute to her class. If each child gets 3 sweets, she would be left with 30 sweets. If each child gets 4 sweets, she would need 5 more sweets.
A) how many children are there in her class?
B) how many sweets did Miss Lim have at first?

The answer is 35 kids. Onsponge solution is that by adding 1 sweet per child = 30+5 sweets (short fall plus extra). Hence the answer is 35 kids. Using multiples may be very time consuming in this example so Onsponge solution is quick and accurate. But my problem is how to explaib to my gal. She gave me a blank look when I tried to explain :?:

Hi

Yes, answer is 35 kids..

What if the question is :
Ms Lim has 30 sweets to give her students. She would need 5 more sweets if each child were to get 1 sweet each. What is the answer ? .. this should be quite straightforward - 30+5 = 35 ... this is exactly the same reasoning applied to the above problem. Just imagined that each child had 3 sweets each, to give each child 4 sweets means to give each child 1 more .. since 5 more sweets is needed ie total of (30+5), then the number of children = (30 + 5)/1 = 35.

To make the child \"see\" .. start with small numbers - eg. Ms Lim wanted to give her students some sweets. If she were to give each student 3 sweets, she would have 8 left. If she were to give each student 5 sweets, she would be short of 4 sweets (ie need 4 more). How many students were there ?
For this one, start with each student already having the 3 sweets and Ms Lim has 8 sweets, so to give each student, she has to give 2 more to each but she would be short of 4 ie she need a total of (8+4)= 12 so that each student could have 2 more each.

So, number of students = 12/2 = 6

[starry15]

Mathizzzfun,

Thanks v much for the explanation and giving me the p3 link. Indeed V enlightening.

After reading and analyzing, I realized the method and logic is same as the Beef question as posted by rrjan above. Drawing a model out would visually enable the child to ‘see’ why we need to add 30 and 5. Will explain to my kid.

[MathIzzzFun]

starry15:

Mathizzzfun,

Thanks v much for the explanation and giving me the p3 link. Indeed V enlightening.

After reading and analyzing, I realized the method and logic is same as the Beef question as posted by rrjan above. Drawing a model out would visually enable the child to 'see' why we need to add 30 and 5. Will explain to my kid.

u r welcome.. this (was discussed in an earlier post) might help - http://www.flickr.com/photos/62167097@N02/5661546018/in/photostream

cheers.

[YumYum]

Hi,

Wld appreciate help on these Qns:

1. The ratio of the number of angelfish to the number of goldfish in tank A was 9:4. When 60 angelfish and 30% of the goldfish were transferred to tank B, the ratio of the no. Of angelfish to the no. Of goldfish in tank A became 15:7. How many fish were transferred from tank A to tank B?

Thanks

[Essential]

Hi math Guru, are u a math tutor. I am looking for a reliable tutor to help my DS. P6 next year

[MathIzzzFun]

Essential:

Hi math Guru, are u a math tutor. I am looking for a reliable tutor to help my DS. P6 next year

Hi

I m not math guru.. this Topic was started by mathsguru...

I have pm you.

cheers.

[MathIzzzFun]

YumYum:

Hi,

Wld appreciate help on these Qns:

1. The ratio of the number of angelfish to the number of goldfish in tank A was 9:4. When 60 angelfish and 30% of the goldfish were transferred to tank B, the ratio of the no. Of angelfish to the no. Of goldfish in tank A became 15:7. How many fish were transferred from tank A to tank B?

Thanks

Hi

Initially, angelfish : goldfish (tank A) = 9u : 4u
After transfer to Tank B,
angelfish in tank A = 9u - 60,
goldfish in tank A = 0.7 x 4u = 2.8u

so, we have
9u - 60 : 2.8u
= 15 : 7

cross-multiply: 63u - 420 = 42u, 21u = 420
1u = 20

Number of goldfish transferred to Tank B = 0.3 x 4u = 0.3 x 4 x 20 = 24

cheers.

[Essential]

Sorry math is fun, did not get the message from u

[MathIzzzFun]

Essential:

Sorry math is fun, did not get the message from u

Hi

could you check your \"My Private Messages\" after you sign in.. alternatively, you could also click on \"messages\" at the top of the Forum page.

cheers.

[concern_mum]

HI, how to add 1+3+5+7+9+…99