So many people liked the puzzles I posted in Subtraction Problems, Russian Style, that I decided to present a similar collection of multiplication and division puzzles. These two sets of puzzles have one thing in common: kids who go for speed over thinking make mistakes.
Humans have 10 fingers on their hands. How many fingers are there on 10 hands?
This one is from my friend Yulia Elkhimova:
Three horses were galloping at 27 miles per hour. What was the speed of one horse?
Here is a similar invention of mine:
Ten kids from Belmont High School went on a tour of Italy. During the tour they visited 20 museums. How many museums did each kid go to?
How many people are there in two pairs of twins, twice?
Can you add more puzzles to this collection?Share:
It takes 3 minutes to boil 3 eggs.
How long will it take to boil 5 eggs?17 April 2009, 1:37 pm
On average, a rabbit produces 4 offspring every month. If I put a rabbit in a cage for 6 months, how many offspring will it produce?17 April 2009, 2:38 pm
It reminds me of the puzzles along the lines of, “Four painters can paint four houses in four days. How many houses can two painters paint in two days?” (or “A chicken and an half can lay an egg and a half in a day and a half. How long will it take three chickens to lay three eggs?”)17 April 2009, 4:39 pm
This reminds me of the trains leaving from different cities problems I used to do when I was younger. For example if a train leaves one city at a rate of 50 miles an hour and another leaves from the second city at a rate of 40 miles an hour. If the cities are 300 miles apart how long will it take the trains to pass? These are such great problems! I love them!19 April 2009, 1:09 pm
Subtraction and Multiplication Problems by Tanya Khovanova « Konstantin’s Weblog:
[…] on her blog. It would be interesting to know how high school kids perform on the Subtraction and Multiplication Problems now compared to 50 years […]8 December 2009, 7:03 pm
the classic would be “When I was going to Saint Yves I met a man with 7 wives… 7kids, 7 cats, 7 kits, etc.. How many were going to Saint Yves?” I left the majority of the question out for brevity.12 January 2011, 11:52 pm