### If (math version)

If you can solve a literal equation
And rationalise denominator surds,
Do grouping factors (with a transformation)
And state the factor theorem in words;
If you can plot the graph of any function
And do a long division (with gaps),
Or square binomials without compunction
Or work cube roos with logs without mishaps.
If you possess a sound and clear-cut notion
Of interest sums with P and i unknown;
If you can find the speed of trains in motion,
Given some lengths and "passing-times" alone;
If you can play with R (both big and little)
And feel at home with l (or h) and pi,
And learn by cancellation how to whittle
Your fractions down till they delight the eye.
If you can recognise the segment angles
Both at the centre and circumference;
If you can spot equivalent triangles
And friend Pythagoras (his power's immmense);
If you can see that equiangularity
And congruence are two things and not one,
You may pick up a mark or two in charity
And, what is more, you may squeeze through, my son.