Q&A - P5 Math

[doraemo]

MathIzzzFun:

doraemo:

Please help...

A wooden crate had a mass of 24 ½ kg when it was half filled with iron nails. When 11kg of iron nails were taken out, the wooden crate was only ¼ full. What was the mass of the wooden crate and the iron nails when the crate was completely filled with iron nails?

mass of wooden crate + mass of 1/2 (=2/4) of iron nails --> 24.5 kg
mass of 1/4 of iron nails --> 11 kg

mass of wooden crate filled with iron nails
= mass of wooden crate + mass of 4/4 of iron nails
--> 24.5 kg + 2 x 11 kg = 46.5 kg

cheers.

got it ....thank you!

[Breadandmuffins]

HI MathsIzzFun


How do I draw model for this qn?I know how to do it logically but cannot explain well to DS properly as he prefers models.


Thanks.


At first, there were 234 more apples in Stall A than Stall B. After 78 apples were transferred fr Stall B to Stall A and 24 apples were thrown away fr Stall A, there were 4 times as many apples in Stall A as Stall B. How many apples were there in Stall B at first?

[MathIzzzFun]

Breadandmuffins:

HI MathsIzzFun


How do I draw model for this qn?I know how to do it logically but cannot explain well to DS properly as he prefers models.


Thanks.


At first, there were 234 more apples in Stall A than Stall B. After 78 apples were transferred fr Stall B to Stall A and 24 apples were thrown away fr Stall A, there were 4 times as many apples in Stall A as Stall B. How many apples were there in Stall B at first?

http://i49.tinypic.com/rbcms0.png\">

cheers.

[Breadandmuffins]

:thankyou:

[Jamesbond]

Ben sold 1295 chickens and ducks at the market yesterday. The ratio of the number of chickens sold to the number of ducks sold was 4:3. Today, he sold another 685 chickens and ducks. As a result, the ratio of the number of chickens sold to the number of ducks sold for the two days was 2:1. How many chickens did he sell on the second day?

[PapayaDad]

yesterday = 7u

7u=1295
u=185
chicken to duck 4u:3u is 740:555

today = 685

both days = 1295 + 685 = 1980
both days = 3p = 1980
p=660
both days ratio is 2p:1p…1320:660

Yesterday chicken = 740
Both days total chicken = 1320
Today chicken = 1320 - 740=580

check
Today duck = 685 - 580 = 105

Yesterday 740:555
Today 580:105
Both days 1320:630…correct

[Jamesbond]

PapayaDad:

yesterday = 7u

7u=1295
u=185
chicken to duck 4u:3u is 740:555

today = 685

both days = 1295 + 685 = 1980
both days = 3p = 1980
p=660
both days ratio is 2p:1p....1320:660

Yesterday chicken = 740
Both days total chicken = 1320
Today chicken = 1320 - 740=580

check
Today duck = 685 - 580 = 105

Yesterday 740:555
Today 580:105
Both days 1320:630...correct

:thankyou: Papayadad.

[Jamesbond]

Dan had some 50 cent coins and 20 cent coins in the ratio 4:5. He exchanged six 50 cent for 20 cent coins. The ratio of the number of 50 cent coins to the number of 20 cent coins Dan has becomes 1:5. What is the total sum of money that Dan has?

[PapayaDad]

Exchange six 50 cents for fifteen 20 cents


At first 4u:5u
Change -6:+15
End 1p:5p

4u-6…1p
5u+15…5p

Make the part the same

20u-30…5p
5u+15…5p

20u-30=5u+15
15u=45
u=3

At first 4u:5u
At first 12:15
12 fifty cents = 6 dollars
15 twenty cents = 3 dollars
Total : 9 dollars

Check:
At first 12:15
change -6:+15
End 6:30 = 1:5 correct
6 fifty cents = 3 dollars
30 twenty cents = 6 dollars
total : 9 dollars…correct

[Gold]

Hi, this is LS, Heyhoe's son! This is the first time using my own account! I'm so excited!!! :imcool:

Can u please help me with these?
1: In the figure, the length of the smaller square is 16cm and the length of the bigger square is 23cm. Find the shaded area.
Photo will be uploaded in the next msg.
2: this figure is made up of 2 squares and a right angled triangle. Find the shaded area. Thanks :clubmyself: the photos are more than 640 pixels wide. I'll try again.