**Maths Problem Of The Week:**

**Using only addition,**

how do you add eight 8s and get the number 1000?

how do you add eight 8s and get the number 1000?

**Problem of the Week: May - Week 3: 16th - 20th May 2016.**

All Change:

You have 6 coins, namely 1c, 2c, 5c, 10c, 50c.

What amounts up to €1 cannot be made exactly with these coins? For example, it is impossible to make either 4c or 9c.

All Change:

You have 6 coins, namely 1c, 2c, 5c, 10c, 50c.

What amounts up to €1 cannot be made exactly with these coins? For example, it is impossible to make either 4c or 9c.

But the really clever trick is explaining to them why these 'tricks' are maths and not magic. Like all good magicians, you should practice by trying them. Can you explain how they work? This trick will impress even your maths teacher.

1. Think of a number. 2. Double it. 3. Add 10. 4. Add 10. 5. Halve it. 6. Take away your original number. 7. Is your answer 5?

Try this with a different starting number. Did you get a different result? Why does this happen?Write the answer on a piece of paper without letting anybody see it and seal it in an envelope. Have somebody hold the envelope and at the end ask them to open it and reveal the number you wrote at the beginning. Wow, Magic!

**Problem of the Week: Week 2: May 9th – 13th 2016:****Is it Magic or is it Maths?****Here are three 'tricks' to amaze your friends.**But the really clever trick is explaining to them why these 'tricks' are maths and not magic. Like all good magicians, you should practice by trying them. Can you explain how they work? This trick will impress even your maths teacher.

1. Think of a number. 2. Double it. 3. Add 10. 4. Add 10. 5. Halve it. 6. Take away your original number. 7. Is your answer 5?

Try this with a different starting number. Did you get a different result? Why does this happen?Write the answer on a piece of paper without letting anybody see it and seal it in an envelope. Have somebody hold the envelope and at the end ask them to open it and reveal the number you wrote at the beginning. Wow, Magic!

Maths Problem:
Week 1 May 3rd - 6th 2016: A Sudoku puzzle is defined as a logic-based, number-placement puzzle. The objective is to fill a 9×9 grid with digits in such a way that each column, each row, and each of the nine 3×3 grids that make up the larger 9×9 grid contains all of the digits from 1 to 9. Each Sudoku puzzle begins with some cells filled in. The player uses these seed numbers as a launching point toward finding the unique solution.It is important to stress the fact that no number from 1 to 9 can be repeated in any row or column (although, the can be repeated along the diagonals). |

**Maths Problem: Week 4: 25th April:**

Smoke Screen:

If an electric train heads North at a speed of 120 km per hour. The wind blows from the East at a speed of 20 km per hour. In what direction will the smoke from the train tail off?

Smoke Screen:

If an electric train heads North at a speed of 120 km per hour. The wind blows from the East at a speed of 20 km per hour. In what direction will the smoke from the train tail off?

**Maths Problem: Week 3 April 18th:**

The census taker was counting the inhabitants of a town and he was questioning a householder who was a man with a beard. He pointed to another man with a beard who lay fast asleep in a chair by the fire. " Who is he?" the census taker asked. The man replied with this riddle: "Brothers and sisters I have none, but that man's father is my father's son." The sleeping man is his: A. Uncle B. Grandfather C. Son D. Father. ????

The census taker was counting the inhabitants of a town and he was questioning a householder who was a man with a beard. He pointed to another man with a beard who lay fast asleep in a chair by the fire. " Who is he?" the census taker asked. The man replied with this riddle: "Brothers and sisters I have none, but that man's father is my father's son." The sleeping man is his: A. Uncle B. Grandfather C. Son D. Father. ????

**Maths Problem: Week 2: April 11th: A Perfect Number:**

A perfect number is a number that is equal to the sum of all its divisors that are less than itself:

eg 1, 2 & 3 are all divisors of 6 and less than 6. Added together 1+2+3=6. So 6 is a perfect number.

What is the next perfect number after 6? (Hint: It is less than 40.)

A perfect number is a number that is equal to the sum of all its divisors that are less than itself:

eg 1, 2 & 3 are all divisors of 6 and less than 6. Added together 1+2+3=6. So 6 is a perfect number.

What is the next perfect number after 6? (Hint: It is less than 40.)

**Maths Problem of the Week: Week 1 April 4th.**

The Train and the Tunnel.

A freight train, one kilometer long, goes through a tunnel thatn is one kilometer long. If the train is travelling at a speed of 15 kilometers per hour, how long does it take to pass through the tunnel?

The Train and the Tunnel.

A freight train, one kilometer long, goes through a tunnel thatn is one kilometer long. If the train is travelling at a speed of 15 kilometers per hour, how long does it take to pass through the tunnel?

**March Puzzle 3: You have a basket containing 10 apples. You have 10 friends, who each desire an apple. You give each of your friends one apple.**

Now all of your friends have one apple each, yet there is an apple remaining in the basket. How?

Now all of your friends have one apple each, yet there is an apple remaining in the basket. How?

**March Puzzle 2: The diagram shows 3 squares and 2 triangles. Rearrange the matches to make 5 squares and 6 triangles.**

**March Puzzle 1: Alphabetical Order Puzzle:**

Find a number with its letters in alphabetical order. (daichead as béarla)

Find a number with its letters in alphabetical order. (daichead as béarla)

**February Week 4: Problem Of The Week:**

Only for the brave, this one!

This square has eleven letters missing, which you have to replace:

Every row, column AND the main diagonals contain all the letters in the word "BRAVE".

That reminds me, I must see the Postman about all those missing letters.

Only for the brave, this one!

This square has eleven letters missing, which you have to replace:

Every row, column AND the main diagonals contain all the letters in the word "BRAVE".

That reminds me, I must see the Postman about all those missing letters.

**February Week 3:**

**At a school fete people were asked to guess how many peas there were in a jar.**

No one guessed correctly, but the nearest guesses were 163, 169, 178 and 182.

One of the numbers was one out, one was three out, one was ten out and the other sixteen out.

How many peas were there in the jar?

No one guessed correctly, but the nearest guesses were 163, 169, 178 and 182.

One of the numbers was one out, one was three out, one was ten out and the other sixteen out.

How many peas were there in the jar?

An old Mathematics book contained this addition sum which had been marked correct by the teacher:

__February Week 2: Sum-Things Missing Puzzle__An old Mathematics book contained this addition sum which had been marked correct by the teacher:

**The three squares in the diagram are where the paper was so bad I couldn't read them. What were the three missing numbers?**

__February Week 1: The Holiday Headscratcher Puzzle__

**"What day do you go back to school, Horace?" asked his grandmother one day.**

"Well," Horace replied, "Nine days ago, the day before yesterday was three weeks before the second day of term."

If Horace had this conversation on a Sunday, what day of the week did he start school?

"Well," Horace replied, "Nine days ago, the day before yesterday was three weeks before the second day of term."

If Horace had this conversation on a Sunday, what day of the week did he start school?

Tom asked his Granny how old she was. Rather than giving him a straight answer, she replied:

"I have 6 children, and there are 4 years between each one and the next. I had my first child (your Uncle Peter) when I was 19. Now the youngest one (Your Auntie Jane) is 19 herself. That's all I'm telling you!"

How old is Tom's Granny?

__January Week 3: How Old is Granny?__Tom asked his Granny how old she was. Rather than giving him a straight answer, she replied:

"I have 6 children, and there are 4 years between each one and the next. I had my first child (your Uncle Peter) when I was 19. Now the youngest one (Your Auntie Jane) is 19 herself. That's all I'm telling you!"

How old is Tom's Granny?

If you have ten counters numbered 1 to 10, how many can you put into pairs that

add to 10?

How many counters did you use?

How many did you leave out?

Now put the counters into pairs to make 12.

How many counters did you use?

How many did you leave out?

Now put the counters into pairs to make 13.

How many counters did you use?

How many did you leave out?

Now put the counters into pairs to make 11.

__January Week 2: Pairs of Numbers__If you have ten counters numbered 1 to 10, how many can you put into pairs that

add to 10?

How many counters did you use?

How many did you leave out?

Now put the counters into pairs to make 12.

How many counters did you use?

How many did you leave out?

Now put the counters into pairs to make 13.

How many counters did you use?

How many did you leave out?

Now put the counters into pairs to make 11.

Gill is two years old now.

Getting her to recognise her name proved difficult, so we put

the letters G, I, L, L on separate building blocks.

She loves arranging them, but rarely gets them in the right

order.

One day she managed to produce every possible

four-letter ‘word':

GLIL is one such ‘word’.How many different four-letter ‘words’ did she produce that

day?

__January Week 1__Gill is two years old now.

Getting her to recognise her name proved difficult, so we put

the letters G, I, L, L on separate building blocks.

She loves arranging them, but rarely gets them in the right

order.

One day she managed to produce every possible

four-letter ‘word':

GLIL is one such ‘word’.How many different four-letter ‘words’ did she produce that

day?

**12: Two Dice**

Let’s say you roll two dice. When they stop rolling, 5 dots and 2 dots appear on the top of them.

If you add up the dots on the top you'll get 7.

Find all the numbers that can be made by adding the dots on the two dice.

Let’s say you roll two dice. When they stop rolling, 5 dots and 2 dots appear on the top of them.

If you add up the dots on the top you'll get 7.

Find all the numbers that can be made by adding the dots on the two dice.

**11. Largest Even Stage: 1**

I have a pile of nine digit cards numbered 1 to 9.

I take one of the cards. It is the 3.

Which card would you choose to go with the 3 so you could make the largest possible two-digit even number with the two cards?

We put the cards back in the pile. This time, I choose the 6. Which card would you choose this time to go with the 6 to make the largest possible two-digit even number?

Have a go at this with a partner. One of you chooses the first digit from the set of cards. The second person then chooses a card to make the largest possible two-digit even number. You can then swap over.

Try it several times so you are sure you have a good method. Talk about your ideas with your partner so you agree together on a 'best' method.

How would your strategy change if you had to make the largest two-digit odd number?

I have a pile of nine digit cards numbered 1 to 9.

I take one of the cards. It is the 3.

Which card would you choose to go with the 3 so you could make the largest possible two-digit even number with the two cards?

We put the cards back in the pile. This time, I choose the 6. Which card would you choose this time to go with the 6 to make the largest possible two-digit even number?

Have a go at this with a partner. One of you chooses the first digit from the set of cards. The second person then chooses a card to make the largest possible two-digit even number. You can then swap over.

Try it several times so you are sure you have a good method. Talk about your ideas with your partner so you agree together on a 'best' method.

How would your strategy change if you had to make the largest two-digit odd number?

10: Biscuit Decorations nrich.maths.org/roadshow For the Teddy Bears' Picnic Andrew decorated 20 biscuits. He lined them up and put green icing on every second biscuit. Then he put a red cherry on every third biscuit. Then he put a white chocolate button on every fourth biscuit. So there was nothing on the first biscuit. How many other biscuits had no decoration? |

**9: Button-up**

Stage: 1

My coat has four different buttons.

Sometimes, I do them up starting with the top button. Sometimes, I start somewhere else.

How many ways can you find to do up my coat?

How will you remember them?

Do you think there are any more? How do you know?

Stage: 1

My coat has four different buttons.

Sometimes, I do them up starting with the top button. Sometimes, I start somewhere else.

How many ways can you find to do up my coat?

How will you remember them?

Do you think there are any more? How do you know?

**8: Got It!**

This is a game for two players. Start with the target number of 23. The first player chooses a whole number from 1 to 4. Players take turns to add a whole number from 1 to 4 to the running total. The player who hits the target of 23 wins the game. Can you find a winning strategy? Can you always win? What happens if you choose a new target number? What happens if you change the range of numbers you can add? Can you work out a winning strategy for any target and any range of numbers?

This is a game for two players. Start with the target number of 23. The first player chooses a whole number from 1 to 4. Players take turns to add a whole number from 1 to 4 to the running total. The player who hits the target of 23 wins the game. Can you find a winning strategy? Can you always win? What happens if you choose a new target number? What happens if you change the range of numbers you can add? Can you work out a winning strategy for any target and any range of numbers?

**Problem Number 6:**

These Clocks have been reflected in a mirror.

What times do they say?

These Clocks have been reflected in a mirror.

What times do they say?

**3. Maths Problem of the Week:**

**Noah saw 12 legs walk by into the Ark. How many creatures could he have seen? How many different answers can you find?**

**2. Half the pieces of fruit in the bowl are apples. There are also three oranges, two pears and a banana.**

How many apples are there in the bowl?

How many apples are there in the bowl?

1. There are three baskets, a brown one, a red one and a pink one, holding a total of ten eggs.

The brown basket has one more egg in it than the red basket.

The red basket has three fewer eggs than the pink basket.

How many eggs are in each basket?

The brown basket has one more egg in it than the red basket.

The red basket has three fewer eggs than the pink basket.

How many eggs are in each basket?