Students compute ratios and convert them to percentages for candy colors (e.g., 3:10 → 30%) and compare sample percentages to population percentages. Students use language of likelihood when making inferences (e.g., predicting the most common candy color, statements like "likely/unlikely", and the food-truck owner inferring that about one-third of customers spend $21–$30). Students practice interpreting sampling results to decide whether an inference is "likely to be true."

Students answer a question asking "About what fraction of 11-year-olds are likely to be between 55 and 60 inches tall?" and use the fraction 1/2 as a measure of likelihood. Students make qualitative probability judgments when the text tells them to consider the "chance of overlap" between pumpkin populations and when they infer that there is a "higher chance of overlap" or that a pumpkin from either population "can have one of these weights." Students also use fractions and proportions in comparing populations (e.g., visual inferences from dot plots and statements about likelihood of larger pumpkins with fertilizer).

Students encounter a probability value in Phase 4 (Genetic Probability) where they are asked to convert the decimal 0.375 to a fraction (3/8). The materials repeatedly ask students to work with decimals and fractions and include a specific problem that treats 0.375 as a probability. The answer key explicitly lists 0.375 = 3/8, showing that students practice representing a probability in fractional form.

Students draw and label a probability line with 0 (Impossible), 0.5 (Equal Chance), and 1 (Certain) and place events into Unlikely, Equal Chance, Likely categories. Students compute and convert probabilities as numbers between 0 and 1 (e.g., coin toss 1/2 → 0.5 → 50%) in the coin and spinner activities. Students compare numerical probabilities (fractions, decimals, percents) to determine which events are more or less likely and use examples and answer keys that label outcomes as impossible, unlikely, equal chance, likely, or certain.

Students match the term "Probability" to the definition "A number from 0 to 1 that shows how likely something is to happen" and complete fill-in-the-blank items that identify 0.5 for a coin flip, 0 for an impossible event, and 1 for a certain event. Students calculate experimental probabilities as fractions, decimals, and percents (e.g., 59/100 = 0.59 = 59%) and use those decimals to predict counts out of 600 by multiplying the experimental probability by 600. Students record tallies across 10, 50, and 100 trials and observe how relative frequency stabilizes as trial number increases.

Students learn and use probability vocabulary (Certain, Impossible, Likely, Unlikely, Equal Chance) and write definitions and examples on the Probability Vocabulary activity page. Students compute probabilities as fractions, decimals, and percentages (e.g., 1/6, 1/2, 1/100, 0.083, 0.36) in multiple activities and use a probability number line question on the cumulative quiz. Students label events by likelihood and compare experimental and theoretical probabilities (Roll of the Dice, Non-Uniform Events, What Went Wrong?), interpreting outcomes as more or less likely.

Students build sample spaces for compound events using organized lists, tables, and tree diagrams and then compute probabilities as fractions and percents (e.g., P = 1/6, 0.125 = 12.5%, P = 2/6 = 1/3 = 33.3%). Students count favorable outcomes over total outcomes to form probability models and use those probabilities to predict expected counts when repeating an experiment (e.g., 16% of 120 = 20). The lesson asks students to convert probabilities to percents and to interpret what a given percent means in repeated trials (e.g., "What does it mean when we say an outcome has a 25% chance?").

Students represent chance using numeric forms (percentages and fractions) in multiple activities: the Music Playlist assigns genres by percent (40%, 30%, 20%, 10%), Library Hunt asks students to write the number of trials with 4+ rolls as a fraction and convert it to a percent, and several activities have students compute experimental averages from repeated trials. Students run repeated simulations (marbles, dice, number cubes) to estimate how often outcomes occur and answer reflection questions about how likely an outcome is (e.g., whether a Blue marble is 'fairly likely' or how increasing instrumentals changes how soon one appears). The Parent/Answer Key language also refers to chances numerically (e.g., '2 out of 10 chance').

The Parent Plan explicitly states that students should "understand that probabilities range from 0 to 1, with numbers closer to 0 meaning unlikely, closer to 1 meaning likely, and around 0.5 meaning about equally likely or unlikely." Student Activity Question 1 directs students to label 0, 0.5, and 1 on a probability line, name each probability, and provide an example event for each. The answer key gives explicit definitions and examples for 0, 0.5, and 1 (e.g., impossible, equal chance, certain).

Students build and label a probability line with 0, 0.5, and 1 and place events from Impossible to Certain, explicitly linking events to positions on the 0–1 scale. The activity asks students to choose events that are impossible (0), equal chance (0.5), unlikely, likely, and certain (1) and to justify each placement using the shelter data. The probability model and answer key have students compute percentage probabilities for size/color combinations (e.g., 9/60 = 15%) and the simulation asks students to compare observed frequencies to model predictions.

Students compute relative frequencies using the formula Relative Frequency = frequency / total and convert cells to decimals (for example, 18/90 = 0.20 and 42/170 = 0.25). Students create two‑way relative frequency tables whose column or row totals equal 1.0 and use those decimals/percentages to compare groups and state which group is more likely (e.g., "20% of bikers... 25% of drivers... Drivers are slightly more likely"). Several activities ask for probabilities or ask students to interpret proportions as how often or how likely something is to happen.

Students compute and fill relative frequency tables (Activity 17 and other two-way table tasks) and answer questions that require giving fractions and decimals such as "What fraction of evening viewers chose soccer?" with answers like 0.33 and 0.45. The Parent Plan and several activities explicitly direct students to "calculate and compare relative frequencies as fractions, decimals, and percentages," and answer keys show probabilities expressed as decimals between 0 and 1. Students also work with two-way frequency and relative frequency tables in multiple problems, practicing the numerical representation of outcomes.

Students are instructed to convert tally counts into percentages and to build two-way relative frequency tables (e.g., "Calculate Percentages" and "two-way relative frequency table"). Reflection prompts ask students to identify which category combination had the highest or lowest percentage and to note zeros or empty spots in the table. Students use relative frequencies/percentages to describe which activities and times are most or least common and to spot patterns in categorical data.

Students label 0, 0.25, and 1 on a probability line and identify those values as impossible, unlikely, and certain with real-world examples. Students calculate theoretical and experimental probabilities in multiple contexts (marbles, an 8-sided die, spinners) and express probabilities as fractions and decimals while comparing which events are more or less likely. Students build and use probability models (e.g., spinner with 1/6, 2/6, 3/6) and discuss expected long-run frequencies (game with theoretical probability 1/4 and experimental trials), including a case that yields a probability of 1/2.

Students label 0, 0.25, and 1 on a probability line and name each type with examples (Question 38). Students compute theoretical probabilities for marbles and dice (Questions 39, 40, 47), list sample spaces (Question 41), calculate experimental probability from repeated trials (Question 43), and create probability models and tree diagrams for compound events (Questions 44–46). The answer key explicitly labels 0 as impossible, 0.25 as unlikely, and 1 as certain, and shows numeric probability values like 3/10, 3/8, and 7/25 in context.

Students calculate and use relative frequencies in a two-way table (e.g., 12/50 = 0.24 or 24%) and answer questions that compare those decimals to determine which activity/time is most popular. The Activity 4 description and answer key show students converting counts to decimals and using those values to state that reading is most popular in the morning and that 24% of evening students prefer gaming. The Parent Plan and skills list also say students will "use relative frequencies calculated for rows or columns to describe possible association," indicating practice with relative-frequency computations.

Students are asked in Problem 50 to calculate relative frequencies from a contingency table and to "Express your answers as decimals." The answer key lists decimal relative frequencies (for example, 0.40, 0.45, 0.40), so students compute proportions that lie between 0 and 1. The data unit includes several tasks where students work with proportions and frequencies.