Prime × Prime = Prime or Composite?

Prime × Composite = Prime or Composite?

Have you ever noticed that when you add an even number to another even number the sum is always even? Above you can see many similar descriptions of calculations. Click on the link which describes the correct result.

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You have completed this level and can claim a trophy.

Determine the nature of adding, subtracting and multiplying numbers with specific properties.

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Level 1 - Even and Odd Numbers

Level 2 - Positive and Negative Numbers

Level 3 - Prime and Composite Numbers

Challenge - Can you find numbers that will satisfy the Mix And Math Challenge?

Even numbers are exactly divisible by two.

Odd numbers are not exactly divisible by two.

Positive numbers are greater than zero.

Negative numbers are less than zero.

Prime numbers only have two factors.

Composite numbers have more than two factors.

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Danielle Edwards, Twitter

Saturday, June 3, 2017

Transum,

Monday, January 8, 2018

"Magic trick:

Ask a friend to hold an odd number of coins in one hand and an even number of coins in the other but not to let you see. You will be able to work out in which hand the odd number of coins is hidden.

Ask the friend to multiply the number of coins in their left hand by three and the number of coins in their right hand by four then add the two totals together.

If the sum of their totals is odd then the odd number of coins is in their left hand otherwise the odd number of coins is in their right hand.

Can you figure out how this works?

For more mathematical magic tricks see Mathemagic."