2.2 Small Group · Group 1
Tier 2 Intervention · Concrete-Representational-Abstract (CRA) · Dual-Language Anchors
Display Data with Histograms · Histogram · Procedural Fluency · Real-World Applications
- A histogram is a bar graph that groups numbers into equal ranges called intervals. The height of each bar is the frequency: how many values fall in that interval. The bars touch because the intervals are continuous. We'll walk through a worked example, try one together, then you'll try a few with hints right there when you need them.
- My data: 3, 7, 12, 15, 18, 24. I will use intervals of 10: 0–9, 10–19, 20–29.
- Interval 0–9: the values 3 and 7 fit, so the frequency is 2.
- Interval 10–19: the values 12, 15, and 18 fit, so the frequency is 3.
- Interval 20–29: only the value 24 fits, so the frequency is 1.
- Now I draw three bars with heights 2, 3, and 1, touching each other. The tallest bar (10–19) is where most values are.
- Display Data with Histograms (Representar datos con histogramas) — Group numerical data into intervals and show each interval's frequency with a bar.
- Histogram (Histograma) — A bar graph that groups data into equal ranges. The bars touch.
- Frequency (Frecuencia) — How many times a value shows up.
- Interval (Intervalo) — A range of numbers used to group data.
- Distribution (Distribución) — How the data is spread out.
- Variability (Variabilidad) — How spread out the numbers are.
- A common mistake in Display Data: Histograms is counting a boundary value in two intervals at once — for example, putting the value 10 in both the '0–9' bin and the '10–19' bin. Each data value belongs to exactly ONE interval. Before you submit, add up all your frequencies and check that the total matches the number of data values you started with.
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1 MULTIPLE CHOICE
In a histogram, what does the height of each bar represent?
- AThe average of the data in that interval
- BThe range of the interval
- CThe median of the data
- DThe frequency (count) of data in that interval
✏️ Workspace & Solution Steps -
2 DRAG SORT
Order the steps for making a histogram.
- Step 1: Choose equal-sized intervals that cover all the data
- Step 2: Count how many data values fall in each interval (frequency)
- Step 3: Draw bars for each interval — height = frequency
- Step 4: Make sure bars touch with no gaps
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3 MATCHING GAME
Match each word to what it means on a histogram.
- Frequency
- Interval
- Bars touch
- AHow many values are in an interval (the bar height)
- BAn equal-width range like 10–19
- CWhy a histogram has no gaps between bars
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4 MULTIPLE CHOICE
A histogram shows these frequencies: 0–4: 3 players, 5–9: 8 players, 10–14: 12 players, 15–19: 5 players. How many players are represented in total?
- A20
- B15
- C28
- D12
per 1 - 1LabelWrite what each column is.
- 2Find per 1Divide to get one.
- 3ScaleMultiply up to what is asked.
- 4CheckDoes the size make sense?
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5 MULTIPLE CHOICE
How is a histogram different from a regular bar graph?
- AThere is no difference
- BHistogram bars touch (no gaps) because the intervals are continuous ranges
- CHistograms use colors and bar graphs don't
- DBar graphs show numbers and histograms show words
✏️ Workspace & Solution Steps -
6 MULTIPLE CHOICE
A histogram has intervals: 0–4, 5–9, 10–14, 15–19. What is the width of each interval?
- A10
- B19
- C5
- D4
✏️ Workspace & Solution Steps
Group Discussion Prompt: How does your visual model justify your mathematical solution?
Partner A: "I modeled this by identifying the relationship and..."
Partner B: "I agree with your step because the standard mathematical rule states..."
Complete each sentence stem to demonstrate precise mathematical reasoning:
Writing Task: Justify why your mathematical solution is accurate and complete.