Q&A - P4 Math

[chloecube]

Thein:

Hi chloecube


I prefer MM method. I don't know whether this is hot or cold

Regarding the problem:

James has some marbles. If he packed them into box of 6, he will have 2 left. If he pack them in box of 7, he will be short of 11. How many marbles does he have?

There is a chance of placing 7 marbles as one group if we pack them 7 as 1 group. So the remaing marbles should be 4 not 11(As nebbermind said)...
Hence the answer can be 38 too....

Regarding this problem :
Lester had some toy animals. If he put them into groups of 5, he would have 2 toy animals left over. . If he put them into groups of 7, he would be short of 3 toy animals. What is the smallest number of toy animals he could have?

Using MM method the answer shud be 32.

If you go for MD.... u get 2u = 5.... quite confusing....

hi,
ya, that is what i am trying to say. sometime MD dun work, so have to try MM
ok, i will tell DS to try one method first, if cannot, then try another.
hope is not too confusing for him

[CoffeeCat]

chloecube:

thks for the short-cut method

meaning for this question, MD is not possible rite?
i am trying to understand this and how to tell my DS when to use MM or MD.

Ya.
When to use a method depends on the question.
So first your son must figure out whether the groups must be equal or need not be equal.
Equal use MD, need not equal use MM... Hope this is simple

Cannot anyhow try methods recklessly in random order, because wrong method can get an answer. Most students will just submit that first answer.

[chloecube]

CoffeeCat:

chloecube:

thks for the short-cut method

meaning for this question, MD is not possible rite?
i am trying to understand this and how to tell my DS when to use MM or MD.

Ya.
When to use a method depends on the question.
So first your son must figure out whether the groups must be equal or need not be equal.
Equal use MD, need not equal use MM... Hope this is simple

Cannot anyhow try methods recklessly in random order, because wrong method can get an answer. Most students will just submit that first answer.

see some light now
:thankyou: everyone

[AgonyMum]

Thanks so much, Thein

And Thanks so much too MathIzzzFun

[Thein]

You are most welcome AgonyMum

[ttyh]

Need help…

1) Figure out a formula that tells the sum of all the whole numbers between any 2 whole numbers. Show how you did it? What is the sum of all numbers between 1000 and 2000?
Thanks

[tianzhu]

ttyh:

Need help...

1) Figure out a formula that tells the sum of all the whole numbers between any 2 whole numbers. Show how you did it? What is the sum of all numbers between 1000 and 2000?
Thanks

Hi

Good Morning.

This is similar to a regular question in primary school maths.

Find the sum of the first 100 whole numbers.

First thing first, do you intend to include 1000 and 2000 in your calculations?

You’ve used “between 1000 and 2000”, this signals that you intended to have the sum of numbers from 1001 to 1999.

Actually, you don’t need any formula.

Write the sequence \"forward and backwards”

1001 + 1002 ------------------- 1999
1999 + 1998 ------------------- 1001

Add vertically

3000 + 3000 -------------------- 3000

This is twice the sum.

The number of terms/integers is 999.

Hence the answer is 999(3000)/2 -------- 1498500

Best wishes

[ttyh]

Thanks Tian Zhu

But the question specifically asked to figure out a formula…how?

[MathIzzzFun]

ttyh:

Thanks Tian Zhu

But the question specifically asked to figure out a formula....how?

Hi

sum
= (number of terms) * average of (1st term + last term)
= (number of terms) * (1st term + last term)/2


cheers.

[ozora]

need some guide on the following question.

Sue and Shaq spend $95 altogether. If Sue spent $15 less, she would have spent thrice as much Shaq. How much did Sue spend?
Is it $75?