Skip to main content

Arithmetic Equation Lesson 1

My son is entering Primary 3 next year and we will soon be introduced to those Arithmetic questions that require a bit of thinking to get the answer. The challenge is you can't use Algebra to answer the question.

Below is the introduction to such a question.

Amanda and Mary had 28 stickers altogether.
Amanda had 10 stickers more than Marry
How many stickers did Mary have?

Block diagram












Initially my approach was this and found it was wrong. I took 28/2-10=8 (Mary having 8 stickers) thinking that if you took the total and divide by 2, both will get the same amount. Since one got 10 more, the other would have gotten 10 less.

However, you don't get the right answer when you check. If Mary had 8 stickers, this means Amanda would have gotten 18 stickers. So 8+18=26 which is the wrong answer.

I tried an alternative approach which I read somewhere that you subtract the total with the difference and divide it by 2. 

Arithmetic 
Step 1: 28-10=18
Step 2: 18/2=9

So Mary had 9 stickers. If you check the answer, Amanda would have 19 stickers and their total stickers would be 28. 

I tried to convince myself with the working and answer with algebra and it made sense.

Alegebra
Let X be the number of stickers Mary had.
So Amanda had (X+10 stickers).

Step 1: X+(X+10)=28 is the total number of stickers.
Step 2: 2X+10=28
Step 3: 2X=28-10=18
Step 4: X=18/2=9
Mary had 9 stickers. 

As you can see, Arithmetic Step 1 & 2 is equivalent to Algebra Step 3 & 4. As such my 2nd approach is the right and I am now convinced why you deduct the "Differences" from the total and then divide it by 2. 

I expect future questions to  be tougher and I do hope to share with you. 




Comments

Popular posts from this blog

Why is Ramly Burger banned in Singapore?

Yahoo Singapore ran an article of the Ramly Burger by highlighting that it is ban in Singapore.

Yet, the writer from Makansutra failed to address the most important issue of why the Ramly meat patty is banned in Singapore.

A search online easily did highlight that the famous Malaysian meat patty is banned by the AVA but didn't go into details.

Wrote Arlina Arshad for The Straits Times in January 2004,

"But the importing of beef and beef products from Malaysia is not permitted, said theAgri-Food and Veterinary Authority (AVA).

Selling and supplying them without a permit is also an offence, and offenders can befined as much as $50,000 or jailed two years, or both, said the AVA."

In May of the same year, another article highlighted that a man was even charged in court for "smuggling" the Ramly burger in 2004.


"The AVA said that meat products processed in Malaysian food factories which it had notapproved were banned here.Suzali was yesterday jailed for four month…

Social Media 101: How To Be The Most Hated Person In Singapore Instantly

It is amazing how we are quick to forget that a single wrong comment on social media can make one the most hated person in Singapore.

Back in 2012, we had Amy Cheong. Her comments on Facebook about a Malay wedding under her HDB void deck resulted in an online CSI that cost her her job.

Fast forward to 2017 and we have Thomas Chua Poh Heng and whose name will forever live in Internet infamy.



Thomas reposted a video of the funeral of a Traffic Policeman who died while on duty. Thomas then commented that his death was well deserve as Thomas was once given a traffic ticket by the same Traffic Policeman.

Even the Home Minister for Singapore, who is responsible for the Police Force, was offended by Thomas' statement.



The screenshot showed that post was marked global by the Globe image next to the Singapore tag which could hint that this post was meant for all to see. As such, the argument of a "private"post does not hold any weight here.

Just as expected, after this post was s…

Google Post Now Available for Google My Business

Google Post, which was previously available for the US Elections in 2016, is now available for all small business who have registered their business with Google My Business.

Google Post allow you to put small snippets about a promotion, event, or show case new products,etc.

Take my company's Google My Business layout above. If you Google "NetGain Systems", you will see the NetGain Systems Pte Lte Google Business Profile. Below the profile is the Google Post of our free IT monitoring software.

According to Search Engine Land,

Google says this give businesses the ability to:

Share daily specials or current promotions that encourage new and existing customers to take advantage of your offers.
Promote events and tell customers about upcoming happenings at your location.
Showcase your top products and highlight new arrivals.
Choose one of the available options to connect with your customers directly from your Google listing: give them a one-click path to make a reservation, sign …