Challenge 18

You have eight matches. Get two squares and four triangles.

Challenge 17

Make 200

1 2 3 4 5 6 7 8 9

Choose four of these digits.

Each one must be different.

Put one digit in each box.

This makes two 2-digit numbers reading across

and two 2-digit numbers reading down.

Add up all four of the numbers.

In this example the total is 100.

12 + 47 + 14 + 27 = 100

1	2
4	7

 

How many different ways of making 200 can you

find?

 

Answers from Poland- Ch.15 and 16

Challenge 16

 

A set of weighing scales measures weight in kilograms. A boy, a girl, and a dog stand on the scales in three different ways.

How heavy would the boy, girl, and dog weigh together?

Challenge 15

Challenge 15
Birds in Trees

There are 2 trees in a garden (tree "A" and "B") and on the both trees are some birds. The birds of tree A say to the birds of tree B that if one of you comes to our tree, then our population will be the double of yours. Then the birds of tree B tell to the birds of tree A that if one of you comes here, then our population will be equal to that of yours. Now answer: How many birds in each tree?

Answer from Greece

ch.14 answers from Poland

CH 14: Some Answers from Spain

Challenge 14

Cut the Cross Puzzle

With two straight lines, cut the Swiss Cross into four congruent pieces which then fit together to make a square

Solution

CH 13: Some answers from Spain

Answers from 6ºA and 6ºB class (11 years old)

Challenge 13 answers from Poland

Challenge13

Challenge 13 (for younger students)

 

Using three straight lines, divide the cabbage patch up into six sections with two cabbages in each section.

Solution to challenge 12

Solution by Lithuanian students

Begin by folding the string in half along its length; this will be 1/3 m.

Fold the 1/3 m length in half, giving 1/6 m.

Finally fold the 1/6 m length back along the length of the string.

The remaining length will be 2/3 1/6 = 1/2 m.

Some answers to challenge 12 from Poland

Answer for challenge 12 from Greece

 

We bend the string in two equal halves. This is equal to 1/3 of the meter. We bend it again in two equal halves. This is 1/6 of the meter. We cut it off and the rest of the string is half a meter.

Pupils of Gymnasio Soufli.

 

Challenge 12 (for 10-11 years students)

A piece of string measures 2/3 m. Without the use of any other measuring tools, how would you use the string to measure 1/2 m?

Challenge 11: Some answers from Spain...

Challenge 11- some answers from Poland

Challenge 11

You are given 18 silver coins but you find out that one of the coins(you kon't know which ) is fake and weighs less than any of the others. How can you be able to detect the false coin using a normal balance scale only three times?

challenge 10

Tom went on a science-and-math quiz show. The science questions were worth 3 points and the math questions were worth 1 point. Tom answered a total of 5 questions and earned 9 points. How many questions did he answer in each category?

Challenge 9

The Headmaster went on holiday to Santander.
During his holidays the following statements were right:

• It rained seven times in the morning or in the aftenoon.
• When it rained in the afternoon, the morning was sunny.
• There were exactly five sunny afternnons and six sunny mornings.

How many days was the Headmaster on holidays?