This is called "Scientific Notation"

So you will always see the 10... Don't worry about it but worry if it is negative or positive because the sign will determine how to move the decimal point.
So, since it is negative then we will be moving the decimal point to the left. And, if it was a positive 3 then we'd move the decimal point to the right!
We will be moving it to the left "3" times because it says - 3 not - 5, etc...

So just move the decimal 3 times in this case and there you go, your standard form. I forgot what the other form is but I can still solve for it...
I hope this helped if you have any questions then feel free to ask!!
Answer:
The probability that the card will be a heart or a face card is P=0.4231.
Step-by-step explanation:
We have a standard deck of 52 cards.
In this deck, we have 13 cards that are a heart.
We also have a total of 12 face cards (4 per each suit). So there are 3 face cards that are also a heart.
To calculate the probability that a card be a heart or a face card, we sum the probability of a card being a heart and the probability of it being a face card, and substract the probability of being a heart AND a face card.
We can express that as:
I don’t know what it is tbh