How did Mr. Gilbreth award odd jobs around the house?
The answer to this can be found on the second page of the book, at least in my edition of it.
The father in the story would award the odd jobs (book says "irregular" jobs) to whoever submitted the lowest bid. In other words, whichever kids wanted some extra money would submit a bid saying how much they would charge to do the job. Whoever asked for the least amount of money would be the one who won and got the job.
This makes sense since Mr. Gilbreth wanted them to all do things more efficiently. So this way he got stuff done for the least amount of money.
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