You know from the rules of divisibility that 10000 is divisible by 2, 4, 5, 8 and 10. Divide it by one of those. The integer you come up with will create a factor pair of 10000.
The product
With whole numbers, there are five ways.
If two numbers have the same sign, their product is positive. If two numbers have opposite signs, their product is negative. So the answer is 'yes'.
The answer is 20000. Simply add the numbers together arithmetically as you would for the problem two plus two. To check your work, a calculator is the best option.
The first two prime numbers after 10000 are 10007 and 10009.
7584
The halfway point between two numbers is calculated by finding the average of the two numbers. In this case, the halfway point between 9990 and 10000 would be (9990 + 10000) / 2 = 9995. This is because you add the two numbers together and then divide by 2 to find the midpoint.
243
10000 and 99999
The answer is 50000. Simply add the numbers together arithmetically as you would for the problem two plus two. To check your work, a calculator is the best option.
The number that is between 8500 and 10000 is 9250. This is simply the midpoint of the two numbers, calculated by averaging them. However, there are many other numbers that also lie between 8500 and 10000, such as 8600, 9000, or 9500.
10000.......1(including 198 zero between 1s)