Milton shuffled slowly along the shelves browsing books. He finally walked up to the counter and handed the girl a book. She looked at the inside cover and told him it would be $3.75. Milton handed her the money and walked away without the book. The girl watched him leave empty-handed but didn’t try to stop him. Why?
Milton was a forgetful and naughty fellow. He was summoning his courage to approach the counter to return his overdue book. The kindly lass at the counter saw the book was 15 days overdue and had accrued the egregious late fee of $3.75 (25 cents a day). Lesson learned, Milton never returned a book late again.
A similar problem can be found in L.A. Graham’s Ingenious Mathematical Problems and Methods with a range of 1 to 9, but the principle remains the same – the numbers with the smallest difference produce the largest product. You start out with the highest two digits, 7 and 6, then attach 5 and 4, putting the smaller of the two digits with the larger number, giving you 74 and 65. The next two highest digits are 3 and 2, giving you 742 and 653. Finally, you add the 1 to the lower number. Page 80 has the details of that solution.
I go up, but at the same time go down, Up toward the sky and down toward the ground, I’m present tense and past tense too, Come for a ride, just me and you.
A zebra was going to the river. On the way the zebra encountered five giraffes. Each giraffe had five monkeys on their neck. How many animals were going to the river?
