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#### Resources tagged with Number - generally similar to Black Box:

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### There are 15 results

Broad Topics > Numbers and the Number System > Number - generally

### Black Box

##### Stage: 5 Challenge Level:

This black box reveals random values of some important, but unusual, mathematical functions. Can you deduce the purpose of the black box?

### The Secret World of Codes and Code Breaking

##### Stage: 2, 3 and 4

When you think of spies and secret agents, you probably wouldn’t think of mathematics. Some of the most famous code breakers in history have been mathematicians.

### N000ughty Thoughts

##### Stage: 4 Challenge Level:

How many noughts are at the end of these giant numbers?

### Factorial

##### Stage: 4 Challenge Level:

How many zeros are there at the end of the number which is the product of first hundred positive integers?

### A Story about Absolutely Nothing

##### Stage: 2, 3, 4 and 5

This article for the young and old talks about the origins of our number system and the important role zero has to play in it.

### More Mods

##### Stage: 4 Challenge Level:

What is the units digit for the number 123^(456) ?

### Multiplication Magic

##### Stage: 4 Challenge Level:

Given any 3 digit number you can use the given digits and name another number which is divisible by 37 (e.g. given 628 you say 628371 is divisible by 37 because you know that 6+3 = 2+7 = 8+1 = 9). . . .

### Euler's Officers

##### Stage: 4 Challenge Level:

How many different ways can you arrange the officers in a square?

### Mod 3

##### Stage: 4 Challenge Level:

Prove that if a^2+b^2 is a multiple of 3 then both a and b are multiples of 3.

### Squaresearch

##### Stage: 4 Challenge Level:

Consider numbers of the form un = 1! + 2! + 3! +...+n!. How many such numbers are perfect squares?

### Big and Small Numbers in Biology

##### Stage: 4 Challenge Level:

Work with numbers big and small to estimate and calulate various quantities in biological contexts.

### Find the Fake

##### Stage: 4 Challenge Level:

There are 12 identical looking coins, one of which is a fake. The counterfeit coin is of a different weight to the rest. What is the minimum number of weighings needed to locate the fake coin?

### Novemberish

##### Stage: 4 Challenge Level:

a) A four digit number (in base 10) aabb is a perfect square. Discuss ways of systematically finding this number. (b) Prove that 11^{10}-1 is divisible by 100.

### Latin Numbers

##### Stage: 4 Challenge Level:

Can you create a Latin Square from multiples of a six digit number?