### Epidemic Modelling

Use the computer to model an epidemic. Try out public health policies to control the spread of the epidemic, to minimise the number of sick days and deaths.

### bioNRICH

bioNRICH is the area of the stemNRICH site devoted to the mathematics underlying the study of the biological sciences, designed to help develop the mathematics required to get the most from your study of biology at A-level and university.

### Conversion Sorter

Can you break down this conversion process into logical steps?

# Mixed up Mixture

### Why do this problem?

This problem gives practice in converting between a variety of measures. Don't be put off if your students are not aware of the meaning of the various reagents: the table can be reconstructed using knowledge of units alone and a little common sense. Engaging with a problem containing some unfamiliar elements is a good general aspect of mathemaical training.

### Possible approach

The most intimidating part of this question is the scientific names of the reagents. Encourage students to see past this to the mathematical structure of the problem. If it helps, the names of the reagents could be replaced by letters.

### Key questions

• What is the question asking mathematically?
• Is it possible easily to rule out certain cards from certain positions? What possibilities remain?

### Possible extension

You might naturally try Real-life equations next.

### Possible support

Change the names of the reagents to letters or something simpler.