Before beginning, make sure your child knows what is in a standard deck of cards. Use the
questions below to teach her. If needed, you might begin by sorting the cards by color and
then by suit and count them. Depending on your child’s prior experiences with cards,
she might already be familiar with the answers. If not, she might want to write down the answer
to each question.
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| How many cards are in a complete deck? |
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| How many cards are black? |
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| How many cards are red? |
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| How many cards are in each suit (diamonds, hearts, spades, and clubs)? |
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| What numbered cards are there? How many are there of each? All together? |
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| What are the face cards? How many are there of each? All together? |
Once your child is familiar with the standard deck of cards, you can use it to investigate
probabilities or chances. The probability of an event occurring (when all events are equally
likely) can be found by dividing the number of possibilities for the named event by the total
number of possibilities. The result is a fraction (which can also be changed to a percent
chance).
For example, the chance of drawing the King of Hearts from a full deck is
1
52
because there is only one King of Hearts in the entire deck and 52 cards
all together (excluding the Jokers). The chance of drawing a black card from a full deck is
12
(one out of two) because there are equal numbers of black and red cards.
This probability can also be thought of as 2652
, since there are 26 black cards and 52 cards all together. These two probabilities
also equal each other:
12=2652.
Think of your own questions for finding probabilities. Here are some to get you started:
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| What is the probability of getting a red card? |
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| What is the probability of getting a heart? |
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| What is the probability of getting a king? |
After exploring the probabilities of drawing a single kind of card from a full deck, look
at what happens when dealing more than one card at a time.
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| After dealing one red card, what is the probability that the second card will be
red? |
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| After dealing two red cards, what is the probability that the third card will be
red? (Remember that there are fewer red cards and fewer total cards each time.) |
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| After dealing one king, what is the probability that the next card will be another
king? |
All of these questions are about single events. The next questions are about compound events
— more than one event occurring at the same time. For these questions, don't be concerned
with exact probabilities. Ask your child to make good guesses and then check the guesses using
experiments.
For each experiment, reshuffle the deck well between tries. You may also want to draw cards
randomly, rather than from the top of the deck. Keep a chart tallying the number of total
tries and the number of successful tries. The probability is the number of successful tries
divided by total tries.
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| What is the probability of dealing three red cards in a row? |
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| What is the probability of dealing two kings? |
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| What is the probability of dealing a jack, a queen, and a king? |
Through these experiments, your child may start to realize that even though the probability
for a single event (getting a red card) is pretty high, the probability gets much smaller
when we consider compound events.
