Estimating and approximating

There are 59 NRICH Mathematical resources connected to Estimating and approximating
Shedding Some Light
problem

Shedding some light

Age
7 to 11
Challenge level
filled star empty star empty star
Make an estimate of how many light fittings you can see. Was your estimate a good one? How can you decide?
Silver Line
problem

Silver line

Age
11 to 14
Challenge level
filled star empty star empty star
Weekly Problem 40 - 2008
A class raises money for charity by placing 10p pieces edge to edge in a 'silver line'. If the line was 25m long, how much money did they make?
Interstellar
problem

Interstellar

Age
11 to 14
Challenge level
filled star empty star empty star
What number could replace * so that */5 is between 3 and 4?
Thunder and Lightning
problem

Thunder and lightning

Age
11 to 14
Challenge level
filled star empty star empty star
How far away was the lightning if the flash and the thunderclap were 6 seconds apart?
Today's date - 01/06/2009
problem

Today's date - 01/06/2009

Age
5 to 11
Challenge level
filled star empty star empty star
What do you notice about the date 03.06.09? Or 08.01.09? This challenge invites you to investigate some interesting dates yourself.
Let's Get Flexible!
article

Let's get flexible!

In this article for primary teachers, Ems outlines how we can encourage learners to be flexible in their approach to calculation, and why this is crucial.
Building Patterns
page

Building patterns

Can you deduce the pattern that has been used to lay out these bottle tops?