Estimating and approximating

Can you work out how many of each kind of pencil this student bought?

Work with numbers big and small to estimate and calulate various quantities in biological contexts.

Get some practice using big and small numbers in chemistry.

Bluey-green, white and transparent squares with a few odd bits of shapes around the perimeter. But, how many squares are there of each type in the complete circle? Study the picture and make an estimate.

Are these estimates of physical quantities accurate?

Mr. Sunshine tells the children they will have 2 hours of homework. After several calculations, Harry says he hasn't got time to do this homework. Can you see where his reasoning is wrong?

How many generations would link an evolutionist to a very distant ancestor?

Find the exact difference between the largest ball and the smallest ball on the Hepta Tree and then use this to work out the MAGIC NUMBER!

The problem is how did Archimedes calculate the lengths of the sides of the polygons which needed him to be able to calculate square roots?

From the information you are asked to work out where the picture was taken. Is there too much information? How accurate can your answer be?