Estimating and approximating

There are 59 NRICH Mathematical resources connected to Estimating and approximating
Biology measurement challenge
problem

Biology measurement challenge

Age
14 to 16
Challenge level
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Analyse these beautiful biological images and attempt to rank them in size order.
Placeholder: several colourful numbers
problem

Counting sweets

Age
7 to 14
Challenge level
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How might you use mathematics to improve your chances of guessing the number of sweets in a jar?
Today's date - 01/06/2009
problem

Today's date - 01/06/2009

Age
5 to 11
Challenge level
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What do you notice about the date 03.06.09? Or 08.01.09? This challenge invites you to investigate some interesting dates yourself.
Approximately certain
problem

Approximately certain

Age
14 to 18
Challenge level
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Estimate these curious quantities sufficiently accurately that you can rank them in order of size
What's My Weight?
problem

What's my weight?

Age
7 to 11
Challenge level
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There are four equal weights on one side of the scale and an apple on the other side. What can you say that is true about the apple and the weights from the picture?