Guess what you’ve been doing!
Were you able to guide Ribidip through the maze to the safety of the
pond? Did you figure out how to get the wolf, the goat, and the cabbages
across the river? Were you able to put the five playing cards in order
in ten moves?
Well, here’s a surprise for you—all the time you were having fun
working out puzzles, you were really doing mathematics!
You may think that mathematics just means doing arithmetic problems.
That’s what many people think. But that’s wrong. Arithmetic is really
only a very small part of mathematics.
Mathematics is a way of thinking things out, step by step, as you have
to do to solve a
The wolf, the goat, and the cabbages
First, the man took the goat across the river. Then he went back and
took the big basket of cabbages across. But when he left the cabbages,
he put the goat into the boat. Then he took the goat back across the
river.
When he reached the side where the wolf was, the man put the wolf into
the boat and left the goat. Then he took the wolf across and left it
with the cabbages. Finally, he went back and brought the goat across
again.
See how easy it was? Were you able to figure it out?
Toothpick teasers
Take away the toothpicks shown in red. (There are a number of ways to
solve the first puzzle. Only four ways are shown.)
puzzle. It’s also a way of using numbers and symbols, as you did to
discover Ribidip’s magic word. And it’s a way of thinking about shapes.
A Mobius strip is a shape that has only one side. A maze is a shape that
has no inside. Why no inside? Because the beginning and the end of the
path do not come together to form a closed shape. And only a closed
shape has an inside and an outside.
So, mathematics is really a way of solving all kinds of puzzles and
tricky problems. And that can be fun! And useful!
Now that you know a little more about what mathematics really is, go on
with this book. You’ll find more puzzles, more surprises, a lot of
things to think about, and a number of things to do. And you’ll find
that mathematics is a lot more fun than you ever suspected I
Answers to Rebus riddles
Cat plus R plus pill plus R = cat r pill r,
or—caterpillar.Doll plus fin = dollfin, or—dolphin.
Pear plus nut is pearnut; minus N is pearut, or—parrot.
Month minus th is mon; plus key is monkey.
L plus F plus ant – L F ant, or— elephant.
Stir minus S is tir; tir plus key is tirkey, or—turkey.
A moving numbers game
Move the 2 to the right
Move the 3 to the right
Move the 4 down
Move the ace (1) to the left
Move the 5 to the left
Move the 2 up
Move the 3 to the right
Move the 5 down
Move the 2 to the left
Move the 3 up
The magic word
If you follow the badger’s instructions very carefully, you’ll find that
you get the number 1089 no matter what number you started with. Now, see
what letter each of the numerals in the number 1089 stands for, and
you’ll have the magic word Ribidip is to shout if the snake tries to eat
him.
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