Q&A - P3 Math

[peapot]

Hi SAHMchew


Why does 80 occupy 2 boxes of yiling? And not just 1 box?

[SAHM Chew]

peapot:

Hi SAHMchew


Why does 80 occupy 2 boxes of yiling? And not just 1 box?

Hmm, I do not quite understand your question. Yiling was cut into 3 small units as after Ming Hao sold 80 of his stamps, Yiling had 3 times as many stamps as him. There are no changes to Yiling's number of stamps. So, we had to cut Yiling 's big unit into 3 smaller units.

[peapot]

After studying the model again, I think I sort of get it already. Thks.

[FRKeon]

Can I know how do we coach our kids for division with the Quotient and Remainder thing by using our 80s’ method?

[veraclari]

hi parents, need to know how teachers teach students to answer the following question without using algebra:


Mrs Ho bakes some cakes for her class. If she gives 2 cakes to each pupil, she will have 17 extra. if she gives 5 cakes to each pupil, she is short of 4. How many cakes did she bake?

Thanks! while I can solve with algebra, can't explain to my kid... TiA! :salute:

[CRAZYBANANA]

Mrs Ho bakes some cakes for her class. If she gives 2 cakes to each pupil, she will have 17 extra. if she gives 5 cakes to each pupil, she is short of 4. How many cakes did she bake?


Can you explain in the following way:
If each kid rec 2 cakes, there are 17 extras;
If each kid rec 5 cakes, there is a short of 4
i.e. when each kid rec 3 more cakes each, add’l cakes req is 17 + 4 = 21
therefore, no. of kids = 21/3 = 7
She must have baked (7 x 2) + 17 = 31
Further checking can be done as (7 x 5) - 4 = 31

[veraclari]

Thanks crazybanana for simplifying e explaination. Appreciate it. 1 kid understand while e other doesn’t hahaha

[plum-cake]

veraclari:

Thanks crazybanana for simplifying e explaination. Appreciate it. 1 kid understand while e other doesn't hahaha

can try this model
http://i39.tinypic.com/90bsir.gif\">

[peapot]

veraclari:

hi parents, need to know how teachers teach students to answer the following question without using algebra:


Mrs Ho bakes some cakes for her class. If she gives 2 cakes to each pupil, she will have 17 extra. if she gives 5 cakes to each pupil, she is short of 4. How many cakes did she bake?

Thanks! while I can solve with algebra, can't explain to my kid... TiA! :salute:

if gives 2 cakes : 17 extra
if gives 5 cakes : short of 4

the difference is 3 cakes : 17+4=21 more cakes

giving extra 1 more cake to each pupil : 21/3 = 7 more

She has 7 pupils in her class.

correct answer?

[kiasu2008]

Hi Parents,


Can help me to solve this question.

Sam, Tara and Xing Yi collected cans for recycling. Sam collected six times as many as Tara. Tara collected 13 cans more than Xing Yi. If they collected a total of 283 cans, how many cans did Tara collected ?