Ah now i understand your difficulty. Of course extrapolation would natrually be associated with math.
So a crude example of something that is easy to extrapolate could be: 1+0=1. 1+1=2. 1+2=3. 1+3=4. From such minimal data one could extrapolate the answer of the next equation. One could even guess what the next question would be.
Conversly something that is hard to extrapolate is for instance the share index of BP (insert any company you like i.e. lehman brothers). So you might see some statistical analysis showing continued growth increasing profit and a fairly sustainable clientele. One might extrapolate data from the 90s and the 00s and predict continued growth and profitability. But the extrapolation can fail when unforseen events take place or missed facts are not taken into account. The projection may fail because in time the outcome would be the exact opposite of the prediction
In an analogical way the theory of evolution shares a great deal in common with "extrapolation". Reading Darwin for the first time i was amazed at both his madness and his intelligence (there is a fine line). Everything i had been taught as a JW had led me to believe he was wholly wrong. In fact i had misunderstood what was written in the societies literature or perhaps i was brought up beyond what was written. I am not sure which. The truth of the matter as i see it is that Darwin was right about a great many things. These days what we call the vast majority of this writings is microevolution. Feel free to insert similar ideas such as adaptation etc.
For example he talked about a north american wolf that he said was the progenitor of two distinct breed of wolves. One on the plains and one on the mountain ranges. The latter had developed vastly superior hind leg strength and the offspring of such was different physically. This is microevolution and i was very grateful to see in recent wt publication the distinction made and no statement saying microevolution is contrary to bible teachings. I had previously come to this conclusion but it is anethma for a JW to accept evolution theory even when the term evolution is preceded by micro. I kept my findings largely to myself until others mentioned the new publication made the differentiation.
Darwin et al no doubt had observed the wolves adapting to their surroundings. One could probably now visit the region and scientifically demonstrate they are from the progenitor and have differences. Observed data could be assessed over the past couple of hundred years to demonstrate mircoevolution. Darwin then makes a fatal mistake. After pages and pages devoted to minute detail regarding evidence collected over a few decades (not just the wolves) he makes an enormous leap and says that if we could turn back the pages of time over millenia we would see the continued gradual change so that originally one or two small progenitor was the initial parent of all in the animal kingdom.
In other words he substanitially demonstrates microevolution. But he then uses this small data collected over a few years and predicts what would happen over millenia. I did the math once and it was something like using 0.0000001% data to predict what would happen in the other 99.9999999%. I cant be bothered to work it out again, but somebody else feel free to do the math.
How this theory is taught in schools in science class is perhaps the greatest miracle of all time. Second perhaps to abio-genesis.
Ps. you said google it and when i did this thread was top and the site below came 3rd. It explains rather more clearly what i have been trying to explain above
www.evolutionnews.org/2012/04/natural_limits058791.html