Red blood cells move in single file through capillaries.
A red blood cell is 8 μm8\ \mu\text{m}8 μm wide.
Calculate the largest number of red blood cells that could fit in single file along a capillary 1 mm long.
A student made a quick estimate of the answer to (a). The student rounded the width of a red blood cell to 10 μm10\ \mu\text{m}10 μm.
Give the student's estimate.
Calculate the percentage difference between the student's estimate and the answer to (a). Use the answer to (a) as the starting value.
Explain when it is appropriate to use an estimate rather than an exact calculation.
48 exam-style questions on Edexcel GCSE Biology 1.2 Number, size and scale, covering 1.2.1 Number, size and scale with estimations and 1.2.2 Quantitative units in relation to cells. Each one has a worked solution and a mark scheme showing where the marks go.