🎲 AINMATH · Classroom Worksheet

Likelihood

Grades 5–6 · Likelihood ⏱ 15–20 min

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Learning goal — Be able to express likelihood as a fraction, and compare the likelihood of different events.

Likelihood = number of favorable outcomes ÷ total number of outcomes

💻 Access on a tablet → ainmath.com/coin-dice-simulator.html

1Expressing Likelihood as a Fraction

① What's the likelihood of getting heads when you flip a coin, as a fraction?

② What's the likelihood of rolling a 3 or higher on a die, as a fraction?

2Comparing Likelihoods

① Which is more likely when rolling a die: getting an even number, or getting a 6?

3Think Further

Q. You flipped a coin 10 times and got heads only 3 times. Does this mean the fact that "the likelihood of heads is 1/2" is wrong? Explain your thinking about the relationship between the number of flips and likelihood.

For teachers — cover before handing out to students

Answers & Solutions

Activity 1 — ① 1/2 ② 3,4,5,6 → 4/6=2/3

Activity 2 — An even number (2,4,6→3/6=1/2) is more likely than rolling a 6 (1/6)

Activity 3 — It's not wrong. A likelihood of 1/2 means heads and tails come up about equally often when you repeat the flip many, many times, so with only a few trials, the result can happen to lean one way by chance. As the number of flips grows, the actual results get closer and closer to 1/2.