Q&A - P5 Math

[bb_ mom]

Can you share how to solve using model?

[MathIzzzFun]

Can you share how to solve using model?

same model method used for similar questions here:

https://www.flickr.com/photos/mathizzzf ... 9537229054

https://www.flickr.com/photos/mathizzzf ... 9537229054

cheers.

[guchengyouzi]

There were 3/5 as many children as adults in the bus. At the next bus stop, 3 children boarded and 2 adults alighted from the bus. Then, there were 5/6 as many children as adults on the bus. How many children were there on the bus at first?


The method from the teacher not able to understand .
How did we get 12:20 .
Can anyone explain please ?

How to post pic here? ^-^

When you click post you'll get to the posting page.
Then scroll down and you'll see tinypic.
So you click browse and select the your graphics file which you have saved in your documents folder (or other name folder)
Click upload. Wait for a few seconds.
Finally click "Add to Post".
If you scroll back up to the usual typing area, you can see the line "[img]something/something/something[img]"
Now you can type your lines

[bb_ mom]

If you encounter clicking "Add to Post" (like I do when using iphone), cut link of the image & paste in the usual typing area. Taught by a few teachers from this forum.

[Sruthi]

. Please help

[jieheng]

. Please help

Noel---[-------240----------][---120--]
Kim----[-------240----------]

Noel---[--][-----------------][---120--]
Kim----[--][--][--][---------]

[--] --> money spent

Noel---[--][--][--][---------][---120--]
Kim----[--][--][--][---------]

[---------] + [---------] -->[--][--][---120--]
[---------] --> [--][-60-]

........[-------240----------]
Noel---[--][--][--][--][-60-][---120--]
Kim----[--][--][--][--][-60-]

[--][--][--][--][-60-] --> [-------240----------]
[--][--][--][--] --> 240 - 60 = 180

Altogether , they spent $180

[Whitearies]

June bought 5 similar pencil cases and 8 similar key chains. Each pencil case cost $1.35 more than a key chain.

If the total cost of the key chains was $14.85 more than the total cost of the pencil cases,

(a) how much did 1 pencil case cost?
(b) how much did June spend altogether?

[guchengyouzi]

June bought 5 similar pencil cases and 8 similar key chains. Each pencil case cost $1.35 more than a key chain.

If the total cost of the key chains was $14.85 more than the total cost of the pencil cases,

(a) how much did 1 pencil case cost?
(b) how much did June spend altogether?

Let the price of a key chain be u

cost of key chains - cost of pencil cases = 14.85
8u - 5 * (u + 1.35) = 14.85
8u - 5u - 6.75 = 14.85
solve for u
u = 7.20
A pencil case cost 7.20 + 1.35 = $8.55
Total spending 5 * 8.55 + 8 * 7.20 = $100.35

[Bubbles168]

For the Noel and Kim question, can solve using units and parts. This method is somewhat like model, see if you understand:

Noel> 1u+3p=360
Kim> 3u+1p=240
Since we are finding units, we need to eliminate the parts.
So,
Kim ×3> 9u+3p=240×3
=720
Noel stays the same> 1u+3p=360
9u-1u=720-360
=360
8u=360
1u=360÷8=45
At first, 4u> 45×4=180
Answer:180

Hope this helps.

[tankee]

anyway to solve this type of qns beside using guess and check?


qns

Ali has more than 30 marbles but fewer than 40 marbles.
If he puts them into groups of 4, there will be a reminder of 3 marbles.
If he puts them into groups of 6, there will be a reminder of 5 marbles.
How many marbles does Ali have?