If tom got 200 euro for his birthday. He spent 1.0 how much did he spend?
you want to reword the question?
He spent 1.0
how much did he spend?
1/10
To find out how much Tom spent, you need to multiply the amount of money he got for his birthday by the percentage (or fraction) he spent.
In this case, Tom spent 1.0 (which can also be expressed as 100%, because 1.0 is equal to the whole amount). So, to calculate how much he spent, you take 200 euros and multiply it by 1.0 or 100%.
200 euros x 1.0 = 200 euros.
Therefore, Tom spent 200 euros.