How to turn string into numbers it represents without using str2num?

The only functions allowed are:

zeros, ones, reshape, repmat, length, size, max, min, mod, all, any, sort, find, floor, ceil, round, log10, sum

[James Tursa]

If you were to do this by hand, do you have any ideas about how you would go about it? E.g., how could you figure out the first digit?

Answer 1

[Walter Roberson]

You cannot do that. Converting a string into a number requires addition (and multiplication makes it easier.) You would also need to index into the string, but indexing is a function.