200 x 100 = 20000
200 times 100 is 20000. Multiplying by 100 shifts every digit two places up, so the 2 and its two zeros pick up two more, giving twenty thousand.
200 × 100 = 20,000
Adding 200 to itself 100 times gives the same answer.
Working out 200 x 100
200 x 100 = 20000. Strip both numbers back to 2 x 1, which is 2, then return the zeros. 200 carries two of them and 100 carries two more, so the answer is a 2 followed by four zeros: twenty thousand.
Twice a familiar answer
200 is double 100, so this product is double 100 x 100. That sum gives 10000, and doubling it gives 20000. If you already know one, you never need to work out the other.
Where 20000 turns up
Dollars become cents by multiplying by 100, so 200 dollars is exactly 20000 cents. The same shift converts metres to centimetres: 200 metres is 20000 centimetres. Any time one unit is defined as a hundredth of another, this is the multiplication that moves between them.
The near miss
200 x 1000 is 200000, ten times larger, and the whole difference is a single zero in the second number. Check that you multiplied by a hundred and not a thousand before writing the total down. The multiplication answers index lists the neighbouring sums.