# What is Cheryl’s Birthday?

Kennethjianwen shared this question on his Facebook page and it went viral. To be sure, MOE has clarified this WON’T be a PSLE question. Still it is a fun logic question. This is the solution. Did you get it right? First we need to figure out if Albert knows the month or the day. If he[…]

# Default title

This is said to be a Maths questions taking from an admission test for a Hong Kong primary school. We can’t verify that. Nonetheless, the question is very interesting and it shows how Maths is about thinking out of the box. What is your answer? ANS: The solution: imagine you are retrieving your car at[…]

# Multiplication short-cut

Sometimes it’s faster during examinations if we could do complicated multiplication mentally. Here’s one short-cut. How to multiply double-digit numbers by 11. Example: MULTIPLY 45 x 11. Step 1: The answer will start with 4 and end with 5. So it’s 4__5 Step 2: Find out what’s in the blank by adding 4+5=9 Step 3:[…]

# Fractions

You can use circles cut into segments to help understand fractions. Here I’ve also used a dodecagon (12-sided polygon). I cut them into two (halves), four (quarters), eight (eights) and so on, and used them to demonstrate addition, subtraction, multiplication and division of fractions for the last session.

# Maths Tricks

Looking to impress your relatives this Chinese New Year? Here are a couple of Maths tricks that you can showcase in front of your cousins! Trick 1: 1. Get them to think of a 3-digit number. 2. Multiply it by 7, 11 and 13 and hey presto, you get twice that number. For example: 1.[…]

# Divisible by 7

How do we know if a number is divisible by 7 without a calculator? Easy. Follow these steps: 1. Take the last digit of the number you’re testing and double it. 2. Subtract this number from the rest of the digits in the original number. -If this new number is either 0 or if it’s[…]

# Real Life Example of Estimation

Was at the supermarket buying mama dishwashing liquid. Mega value 2x 1litre bottles going for \$7.10 versus one 600ml plastic refill for \$1.60. Which is better value? 4 packets of the refill would be 2.4litres which is more than the 2 bottles. Yet it would cost only \$6.40. So it is definitely better value.

# Maths Life Examples

Parents can continuously relate Maths to real-life activities. For example: – estimating the price of a shopping cart the next time you go to the supermarket. – comparing prices of detergent or milk powder with different quantities, which will involve calculating price per litre or kg. – get them involved with mental sums that you[…]

# Bala’s age

This question is quite interesting. How many ways are there to solve it? “When Kok Hwa’s age was twice Bala’s age, Mike’s age was 30. When Mike’s age was twice Kok Hwa’s age, Bala’s age was 21. Given that Mike was the oldest among the three persons, find Bala’s age when Mike was 62 years[…]

# Maths puzzle: 4 people with a canoe

Four adventurers (Alex, Brook, Chris and Dusty) need to cross a river in a small canoe. The canoe can only carry 100kg. Alex weighs 90kg, Brook weighs 80kg, Chris weighs 60kg and Dusty weighs 40 kg, and they have 20kg of supplies. How do they get across? ===================== Chris and Dusty row across, Dusty returns.[…]