I addressed approximation elsewhere but when it comes to entrance papers, there is an alternative style of question which examiners are keen to ask. It involves real-world knowledge and a bit of common sense but can be prepared for using some simple tips.
If you have a child who has never bothered to read the labels on food or drinks packets, then you may have a child who will not know that the ordinary sized bag that sits on the shelf weighs one kilogram. Common knowledge that we take for granted is not automatically there in a ten-year-old.
A typical question will provide a variety of options for the most likely size, weight, volume etc of a given thing.
For example: A bucket is likely to be able to hold how much water?
|100 litres,||500 ml,||10 litres,||5ml|
If the child knows what a litre of water, milk or juice looks like, they can work out that the contents of a bucket are likely to be significantly more than this. However, if they were to try and fit 100 litre packs of juice into a bucket they would soon find out they were fighting a losing battle!
The correct answer would obviously be 10 litres, but it is only obvious as we are familiar with such things. Ask your child to guess the weight / length / volume of things. Make it into a game - give them rewards or points for getting it very close or completely accurate - take away points for answers which are obviously completely wrong.
If (s)he is into cars, let them know that the weight of an average car is about 1500kg so what do they think the weight of a lorry is? What about a 4x4? A Smart Car? Let them research the weight and see what it really is.
How many pencils would it take to stretch from one side of the room to the other? Everyone has a guess then see who is right by letting the child measure it out for real. This sort of practical measurement stands a child in good stead for 'non-calculation' questions that rely on common sense.