A comprehensive guided math unit for TEKS 5.2C focusing on rounding decimals to the nearest tenths and hundredths. Includes a visual anchor chart, scaffolded guided practice, a rigorous STAAR-style independent worksheet, and a detailed teacher answer key with step-by-step explanations.
A rancher recorded that a baby calf gained 0.994 pounds in its first day. What is this decimal value rounded to the nearest hundredth?
F 1.00
G 0.99
H 0.90
J 1.0
Q7
At a Texas agricultural fair, a blue-ribbon watermelon weighed 54.385 kilograms. What is the weight of the watermelon rounded to the nearest hundredth of a kilogram?
Record your answer and fill in the bubbles on the grid to the right. Be sure to use the correct place value.
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Q8
An astronomer measured the distance between two stars in light-years. The exact distance is 4.802 light-years. Which of the following is NOT equivalent to this distance rounded to the nearest tenth or hundredth?
A 4.8
B 4.80
C 4.800
D 4.81
Texas STAAR Prep Standard • Grade 5 Math Page 2 of 2
2.4
Problem 6 Key: Number Line 0.678
Lower boundary: 0.67
Midpoint: 0.675
Upper boundary: 0.68
Explanation: 0.678 is greater than the midpoint 0.675, so it rounds up to 0.68.
Guided Problem 7 Key (Watermelon Snake Skin)
Round 1.462 to nearest tenth. Tenths place is 4, neighbor is 6. Since 6 ≥ 5, we round 4 up to 5. Drop the remaining digits.
Correct: B (1.5)
Decimal Rounding Rodeo Unit • Teacher Keys Page 1 of 2
Independent Practice Answers Decimal Rounding Rodeo
Quick Reference Answer Grid
Q1
Q2
Q3
Q4
Q5
Q6
Q7 (Grid)
Q8
C • 4.7
F • 11.40
B
H • Sage Brush
7.391, 7.412, 7.350
F • 1.00
54.39
D • 4.81
STAAR Question Step-by-Step Explanations
Q1 (Copper Wire): 4.739 to Nearest Tenth
The tenths digit is 7. The neighbor is 3 (hundredths place). Because 3 is less than 5, the tenths digit rests at 7. Drop the other digits to get 4.7. Note: Option C is correct. Option B and A are incorrect hundredth roundings.
Q2 (Track Dash): 11.396 to Nearest Hundredth
The hundredths digit is 9. The neighbor is 6 (thousandths place). Because 6 ≥ 5, we add 1 to the 9 in the hundredths place. This causes a roll-over: \( 0.39 + 0.01 = 0.40 \). The correct answer is 11.40. The final zero must be written!
Q3 (Number Line Model): 8.24
The plotted dot is located at 8.24, which is left of the midpoint 8.25. Because 8.24 is closer to 8.2 than to 8.3, it rounds down to 8.2. Thus, B is the only mathematically true statement.
Q4 (Saddle Blankets Table)
We need a weight that rounds to 1.80 nearest hundredth. Let's test them:
• Crimson Red: 1.842 → 1.84 | • Turquoise: 1.796 → 1.80
• Sage Brush: 1.805 → 1.81 | • Dusty Gold: 1.813 → 1.81 Turquoise Trail (G) is correct because 6 ≥ 5, rolling 1.79 up to 1.80.
Q5 (Multiselect): Rounding to 7.4
To round to 7.4 nearest tenth, the decimal must lie between 7.350 and 7.449.
• 7.391 rounds to 7.4 | • 7.412 rounds to 7.4
• 7.350 rounds to 7.4. All other choices round to 7.3 or 7.5.
Q6 (Calf Gain): 0.994 to Nearest Hundredth
Target is hundredth place (9). Neighbor is 4 (thousandths). Since 4 is less than 5, the hundredths digit stays at 9. Answer is 0.99 (G). (Common mistake: students see double nines and automatically cascade up to 1.00 without looking at the neighbor).
Q7 (Watermelon Griddable): 54.385
We round 54.385 to nearest hundredth. Hundredths place is 8. Neighbor is 5. Since 5 ≥ 5, round 8 up to 9. The final decimal is 54.39. In the griddable, students bubble: 5, 4 before the decimal, and 3, 9 after.
Q8 (Astronomer Distance): NOT Equivalent
Exact distance is 4.802.
• Nearest Tenth: 4.8 (Option A, equivalent to C and B).
• Nearest Hundredth: 4.80 (Option B, equivalent to A and C).
Option D (4.81) is NOT equivalent under any correct rounding rule.
Decimal Rounding Rodeo Unit • Teacher Keys Page 2 of 2
