Q&A - P4 Math

[chloecube]

Q5)


Assuming all are goats,
65 x 4 = 260
260 – 196 = 64
Difference numbers of legs between duck and goat = 4-2 = 2
64/2 =32 ducks
65 – 32 = 33 goats

Check : 32 ducks x 2 legs = 64
33 goats x 4 legs = 132
64 + 132 = 196 legs

Q6)
Assuming all are cows,
75 x 4 = 300
300-220=80
Difference numbers of legs = 4-2 = 2
80/2=40ducks
75-40=35 cows

Check : 40 ducks x 2 legs =80
35 cows x 4 legs = 140
140+80=220 legs

Q7)
Assuming she answered all correctly:
20 x 5 = 100
100 – 79 = 21
Differences = 5+2 = 7
21 / 7 = 3 wrong answers
20 – 3 =17 correct answers

Check: 17 x 5 = 85
3 x 2 = 6
85 -6=79

Q8)

Assuming all coins are 50cents
38 x 50cents = $19
19 – 13.60 = 5.40
Differences = 50-20= 30cents
5.4/ 0.3 = 18 20cents
38 – 18 = 20 50cents
Ratio : 18 : 20
9: 10

i am stuck for Q1,4,9,
Tianshu, can help? thks!

[tianzhu]

chloecube:

i am stuck for Q1,4,9,
Tianshu, can help? thks!

Hi

Please see this earlier solution for a similar question.It should help to answer 1 and 4.

Best wishes

http://farm6.staticflickr.com/5092/5424577928_4b58b5019e_z.jpg\">

[tianzhu]

chloecube:

i am stuck for Q9.
Tianshu, can help? thks!

Hi

This question is given a slight tweak.

A quick one without slide presentation due to time constraints.

Cows ----- 4 legs
Goats ----- 4 legs
Chickens ----- 2 legs

Assume all were chickens; we’ll have 32*2 or 64 legs.

92 – 64 ----- 28
4-2 ----- 4
28/2 ------ 14

Hence, we’ve 14 cows and goats.

32-14 ----- 18

There are 18 chickens

There are 3 times many chickens as cows
18/3 ----- 6
There are 6 cows

14 – 6 ------ 8
There are 8 goats

Best wishes

[tianzhu]

CNS:

Thanks ! Can provide the answers as well ?

Hi

I am sorry.I don't have the answers for 1 to 5.

I'll try to work out the answers at a later time.

Best wishes

[tianzhu]

Hi chloecube and mmpiglet


Sometimes you may see some tweaks in “Make a Supposition” types of questions.

Q2 to Q5 are for upper primary maths.

1) Mei Feng paid $25 for 35 pens and pencils altogether. The pens were sold at $2 each and pencils were sold at 3 for $1. How many pencils did she buy?(8 pens, 27 pencils)

2) There are 85 plates of fried noodles for 80 people. Each adult eats 2 plates of fried noodles and every 3 children share 1 plate of fried noodles. How many adults and how many children are there? ( 35 adults and 45 children)

3) 360 teachers and pupils participated in tree planting.
Each teacher planted 3 trees and each group of 3 pupils planted 2 trees.
If 520 trees were planted altogether, how many pupils were there? (240)

4) 20 boys and girls sold tickets for a funfair. Each ticket was sold at $5.Each boy sold 5 tickets and each girl sold 3 tickets. The amount collected by the boys was $20 more than the amount collected by the girls. Find a) how many girls were there in the group b) how many tickets were sold altogether? (8 boys, 12 girls, 76 tickets)

5) A class of 40 pupils helped to carry bundles of old newspapers in an event organised to collect funds for the old folks. Each boy carried 3 stacks of newspapers and each girl carried 2 stacks. Altogether, the boys carried 30 more stacks than the girls. What is the ratio of the number of boys to the number of girls in the class?

Best wishes

[chloecube]

thks Tianzhu, pls correct me if i am wrong


Q1)
12 x 4 = 48
48 – 36 = 12
Difference = 4 + 2 = 6
12 / 6 = 2 birds
12-2 = 10 hamster

i have got all the answers, except for Q4

[chloecube]

tianzhu:

Hi chloecube and mmpiglet


Sometimes you may see some tweaks in “Make a Supposition” types of questions.

Q2 and Q3 are for upper primary maths.

1) Mei Feng paid $25 for 35 pens and pencils altogether. The pens were sold at $2 each and pencils were sold at 3 for $1. How many pencils did she buy?

2) There are 85 plates of fried noodles for 80 people. Each adult eats 2 plates of fried noodles and every 3 children share 1 plate of fried noodles. How many adults and how many children are there? ( 35 adults and 45 children)

3) 360 teachers and pupils participated in tree planting.
Each teacher planted 3 trees and each group of 3 pupils planted 2 trees.
If 520 trees were planted altogether, how many pupils were there? (240)

Best wishes

hi tianzhu,
i will try out the questions,have to try out and understand before teaching my DS. i feel satisfied when i managed to solve it, and really hope DS can absorb what i teach..

you have been really helpful, you are my on-line teacher

[Yutan]

tianzhu:

chloecube:

i am stuck for Q1,4,9,
Tianshu, can help? thks!

Hi

Please see this earlier solution for a similar question.It should help to answer 1 and 4.

Best wishes

http://farm6.staticflickr.com/5092/5424577928_4b58b5019e_z.jpg\">

Hi, the answer for q1 is 10 Hamsters 10 and 2 birds

[tianzhu]

chloecube:

thks Tianzhu, pls correct me if i am wrong


Q1)
12 x 4 = 48
48 – 36 = 12
Difference = 4 + 2 = 6
12 / 6 = 2 birds
12-2 = 10 hamster

i have got all the answers, except for Q4

Hi

Your answer for Q1 is correct.

For Q2, it's 14.

Best wishes

[tianzhu]

CNS:

Thanks ! Can provide the answers as well ?

Hi

I've added answers for Q1 to Q5 and also a new question (Q10).

Best wishes