Everyday Life Maths Question

Here is the pricing for economy rice from a typical coffee shop.
The question is:

Question

Based on the pricing (first three from left to right), how much does the rice cost ? Also, based on all the four pricings, which one is considered not fair?

You see, maths question is everywhere. Just keep your eyes open.

PSLE 2009 Question

Question

From ChannelNewsAsia: Jim bought some chocolates and gave half of it to Ken. Ken bought some sweets and gave half of it to Jim. Jim ate 12 sweets and Ken ate 18 chocolates. The ratio of Jim's sweets to chocolates became 1:7 and the ratio of Ken's sweets to chocolates became 1:4. How many sweets did Ken buy?

Answer

Primary 5 Question

Question

20% of John's savings is $120 more than 30% of Brian's savings.
After John spends 5/6 of his savings, and Brian spends 1/2 of his savings, John has $20 more than Brian. How much did John and Brian save ?

Answer

Primary 6 Question

Question

There were 40 more raisin buns than strawberry buns. After 3/4 of the raisin buns and 4/5 of the strawberry buns were sold, there were 28 buns left.

(a) How many strawberry buns were there at first?

(b) What fraction of the buns sold were raisin buns?

Answer

Distance/Speed/Time Question

Question

This question came from my reader's comment

Distance between Town X and Y is 100km.
At 07:00, Sam left Town X and cycled towards Y.
Ann left Town X and cycled towards Y at 07:30.
Ann's cycling speed was 4 km/h faster than Sam. At 10:00, Ann caught up with Samuel. When Ann was 28 km from town Y, she stopped to wait for Samuel.

(a) How far was Samuel from Ann when she stopped to wait for him?

(b) How many minutes did Ann wait for Samuel?

Answer

First answer is kind of model-based, but a bit too long. I prefer the second method which uses a triangle to represent distance/speed/time relationship. Although there is little bit of algebra, I think the kid should be able to handle it.

Dear Readers

Thank you for posting all the comments and questions. My primary goal of this blog is to show my readers that most (I would think 90%) of the primary school maths questions can be solved using model based approach. I hope you can learn some of the tricks along the way and able to guide your kid in their problem sum

FYI, I will try to answer your questions if you also give it a try.

Hope this blog can help the parents as well as the kids.

Primary 6 Problem Sum

Question

A box contained 50¢ coins and 20¢ coins in the ratio 2:3. When I took out four 50¢, exchanged them for 20¢ coins, and put then put the money back into the box, the ratio became 2:7. Find the sum of money in the box.

Answer

Two different ways to solve this problem