Q&A - P3 Math

[Applelyn1]

Thanks Mrs Alan, I got the same answer too, wondered why teacher gave answer as 39?

alan000:

Dear Applelyn1,


Age difference remains the same.

In this case, 39 - 9 = 30

When the father is twice as old, the father is 2 units and the son is 1 unit.

The difference -> 2u - 1u = 1u

As difference in age always remains the same,
1u -> 30

Therefore, the son is 30 yrs old now.

Hi Alan

Thanks, I got the same answer too, I wondered why the school teacher gave answer as 39?


To find the current age of the father, find 2u.

That is, 2u x 30 -> 60

The father is 60 years old.

Hope this helps.

Mrs Alan

[Applelyn1]

MathIzzzFun:

Applelyn1:

Need help on this


when my father wa 39, I was 9. now he is twice as old as I am. How old am I?

Thank you in advance.

Hi

Age difference or age gap will always remain the same - this is the most important fact for questions on age.

age gap --> 39 - 9 = 30 = my present age (since father is twice as old, present age = age gap....draw a model --> easier to see with a model)

Thanks!

cheers.

[peapot]

Pls let me know what method to use for this q.


The difference between 2 numbers is 66. When the bigger number is divided by the smaller number, the quotient is 7. Find the bigger number.

I taught my child to use "guess and check". Is there any better way??

[Funz]

Is the answer 77? I did it this way. Let the smaller number be ‘u’


It says the ‘difference between the numbers is 66’. So the bigger number will be
u+66

‘When the bigger number is divided by the smaller number, the quotient is 7’ means
7 = u+66/u

The rest, algebra.
7u = u+66
7u-u = 66
6u = 66
u = 66/6 = 11

The bigger number will be 11 + 66 = 77

[peapot]

Yes Funz, answer is 77 but the child not taught algebra. That’s why I use the guess and check method. Thinking whether anyone has any other method??

[PiggyLalala]

peapot:

Pls let me know what method to use for this q.


The difference between 2 numbers is 66. When the bigger number is divided by the smaller number, the quotient is 7. Find the bigger number.

I taught my child to use \"guess and check\". Is there any better way??

When the bigger number is divided by the smaller number, the quotient is 7.
That is to say the bigger number is 7 times the smaller number.
Hence bigger number = 7u or 7 boxes ( for model)
smaller number = u or 1 box (for model)
Difference = 66
therefore 6u = 66
1u = 11
bigger number = 7u = 77

[Funz]

peapot:

Yes Funz, answer is 77 but the child not taught algebra. That's why I use the guess and check method. Thinking whether anyone has any other method??

Yah. My brain is stuck using algebra.

Gotta use algebra to find answer then work backwards to draw models for DD.

Smaller number is []
bigger number is [] [] [] [] [] [] []

bigger number is 66 more then smaller number. Going by the drawing, bigger number has 6[] more then smaller number, 6[]=66

so each [] is 11
bigger number is 77.

[peapot]

Yes, Yes, yes!!! thanks mummies!!!

[bumbum]

Can someone please help on this question?


Jack sold a total of 285 apples and pears. He sold twice as many apples as as pears. how many more apples than pears did he sell?

[tianzhu]

bumbum:

Can someone please help on this question?


Jack sold a total of 285 apples and pears. He sold twice as many apples as as pears. how many more apples than pears did he sell?

Hi

Good Morning.

You may use MD.

Apples ------ 2 units
Pears ------- 1 unit

3 units ------- 285
1 unit ------- 95

He sold 95 more apples than pears.

Best wishes