Friday, 3 April 2015

Shaking Hands Solution

3 people = 3 handshakes
4 people = 6 handshakes
5 people = 10 handshakes

The answers are all triangular numbers.  If you do not know what triangular numbers are, go and look them up.

Painted Cubes ***



A 3 x 3 x 3 cube is painted red on the outside.  If it is broken up into 1 x 1 x1 – unit cubes, how many of these small cubes have 3 faces painted?  Two faces painted?  One face painted?  No faces painted? 

Hint: Imagine or draw a cube with each face looking like the 3 x 3 grid below.  (Unfortunately the picture I had of a cube will not show up here.)  You could even build one with small blocks!










  

Extend your thinking *****
What about if you start out with a larger cube?  Can you come up with a general rule for an n x n x n cube?

I would very much like to see any answers you are able to come up with!

Happy Easter,
Mrs Hopkins

Thursday, 26 March 2015

Sequence ****

What is the next number in the following sequence?

15, 78, 456, 2724...

Hint: Two operations (out of adding, subtracting, multiplying, dividing) are needed to get to the next term.

Sequence Solution

16, 332 is the next number.  The term-to-term rule is subtract 2 then multiply by 6.

Friday, 20 March 2015

Domino Jigsaws ****



Can you arrange a set of dominoes (up to double sixes) onto these mats.  Each number refers to the number of dots on each domino. 


4


5


3


1


3


3


3


3



0


5


5


1


0


3


1


1


0


0


0


1



4


4


6


6


1


1


6


3


1


2


2


3



0


4


4


2


4


4


4


2


5


5


5


5




0


0


6


6


2


2


6


6


2


2


6


5


If you find a solution, draw it out and show it to Mrs Hopkins.  Do you think there is more than one solution?

Countdown Solutions

Using the numbers 2, 3 and 6, and any of the four mathematical operations:
6 + 3 + 3 = 11
2 x 3 + 6 = 12
6 x 2 + 3 = 15
6 + 3 - 2 = 7
6 x 3 + 2 = 20
3 x 2 x 6 = 36
6 - 3 - 2 = 1 or (6/3) / 2 = 1
6 - (3 - 2) = 1
(3 + 6) x 2 = 18
(6 + 2) x 3 = 24

You might have found some different solutions that work as well.

Friday, 6 March 2015

Multiple Choice Maths **



Find the answers to these problems.  Challenge yourself to calculate the solutions mentally.

1. A tree was planted in 1998.  How old will it be in 2020?
A – 12 years old
B – 22 years old
C – 32 years old
D – 42 years old

2. Which number is nearest to 1000?
A – 909
B – 960
C – 1039
D – 1049

3. What is half of 56?
A – 29
B – 28
C – 27
D – 26

4. My book has 144 pages.  I have read 40 pages.  How many pages do I need to read until I am halfway through the book?
A – 31 pages
B – 32 pages
C – 72 pages
D – 188 pages