Mr Nizam's e-classroom
Mathematics & Science
Heuristics Skills
Heuristics Skills are non-routine word problems which require students to apply certain methods to solve them.
Common heuristics skills : Guess & check, systematic listing, working backwards
1) Sum of many numbers
How to solve 1 + 2 + 3 + 4 + 5 ... 99 + 100 ?
If you are going to add up one-by-one or even press the calculator one-by-one, you are going to spend the entire
exam duration on this question which is worth a few marks!
Here's how...
1) If there's even pieces of numbers - like 1, 2...100 have 100 numbers (even) - Click here
2) If there's odd pieces of numbers - like 1, 2... 49 have 49 numbers (odd) - Click here
(Both methods are about the same)
Practice questions:
1) Exercise 2 - Click here
2) Guess & check
How to identify?
Guess & check questions usually involve number of animals with the number of legs, number of vehicles (like cars and motorcycles) with the number of wheels and many other combinations.
Example question:
In a farm, there were 50 cows and chickens.
Given that they had a total of 146 legs altogether, how many cows were there?
How to solve?
There are 2 ways which you can solve guess & check questions:
1) using a table - Click here
2) using assumption - Click here
Practice questions:
1) Exercise 1 - Click here
3) Systematic Listing
How to identify?
Usually the question involves 2 or more situations. For primary level, just 2 situations. In each situation, there will be an excess (extra) or shortage of the items in the question.
Example question:
Rahman shared some stickers with his friends.
If he gives 7 stickers to each of his friends, he will have 2 stickers left. (excess/extra)
If he gives 8 stickers to each of his friends, he will be short of 1 sticker. (shortage)
Given that he has less than 50 stickers, how many stickers did Rahman have at first?
How to solve?
Using a table - Click here