MATH 0925 MODULE 6 EXAM STUDY PACK
TOPICS COVERED:
* Decimals
* Place Value
* Expanded Form
* Word Form
* Standard Form
* Rounding
* Decimals to Fractions
* Fractions to Decimals
* Comparing and Ordering Decimals
* Perfect Squares
* Square Roots
* Rational and Irrational Numbers
* Adding Decimals
* Subtracting Decimals
* Multiplying Decimals
* Dividing Decimals
* Mean
* Median
* Mode
* Range
FLASHCARDS
Q: What is the tenths place?
A: The first digit to the right of the decimal.
Q: What is the hundredths place?
A: The second digit to the right of the decimal.
Q: What is the thousandths place?
A: The third digit to the right of the decimal.
Q: Write 0.352 in expanded form.
A: 3(0.1) + 5(0.01) + 2(0.001)
Q: Write 4.2706 in expanded form.
A: 4 + 2(0.1) + 7(0.01) + 6(0.0001)
Q: How do you write a decimal in word form?
A: Read the whole number, say “and,” then read the decimal part and its place value.
Q: Write 24.9 in word form.
A: Twenty-four and nine tenths.
Q: How do you round decimals?
A: Look at the digit to the right of the rounding place.
Q: What happens when the next digit is 5 or more?
A: Round up.
Q: What happens when the next digit is less than 5?
A: Keep the digit the same.
Q: Convert 0.46 to a fraction.
A: 46/100 = 23/50.
Q: Convert 0.12 to a fraction.
A: 12/100 = 3/25.
Q: Convert 0.105 to a fraction.
A: 105/1000 = 21/200.
Q: How do you convert a fraction to a decimal?
A: Divide numerator by denominator.
Q: How do you compare decimals?
A: Compare digits from left to right.
Q: Which is greater, 0.20 or 0.12?
A: 0.20.
Q: Which is greater, -8 or -9?
A: -8.
Q: What is 1²?
A: 1.
Q: What is 2²?
A: 4.
Q: What is 3²?
A: 9.
Q: What is 4²?
A: 16.
Q: What is 5²?
A: 25.
Q: What is 6²?
A: 36.
Q: What is 7²?
A: 49.
Q: What is 8²?
A: 64.
Q: What is 9²?
A: 81.
Q: What is 10²?
A: 100.
Q: What is 11²?
A: 121.
Q: What is 12²?
A: 144.
Q: What is √36?
A: 6.
Q: What is √49?
A: 7.
Q: What is √81?
A: 9.
Q: What is √121?
A: 11.
Q: What is √(16/49)?
A: 4/7.
Q: Is √(-100) a real number?
A: No. It is not a real number.
Q: What is a rational number?
A: A decimal that stops or repeats.
Q: What is an irrational number?
A: A decimal that never stops and never repeats.
Q: Is π rational or irrational?
A: Irrational.
Q: Is √2 rational or irrational?
A: Irrational.
Q: What is the rule for adding decimals?
A: Line up decimal points.
Q: What is the rule for subtracting decimals?
A: Line up decimal points.
Q: What is the rule for multiplying decimals?
A: Multiply normally and count decimal places.
Q: What is the rule for dividing decimals?
A: Make the divisor a whole number.
Q: What is the mean?
A: Average.
Q: How do you find the mean?
A: Add all values and divide by the number of values.
Q: What is the median?
A: The middle value after ordering the data.
Q: What is the mode?
A: The value that appears most often.
Q: What is the range?
A: Largest value minus smallest value.
IMPORTANT EXAM RULES
1. Line up decimals when adding and subtracting.
2. Count decimal places when multiplying.
3. Make the divisor a whole number before dividing.
4. Memorize perfect squares from 1² through 12².
5. Rational numbers stop or repeat.
6. Irrational numbers never stop and never repeat.
7. Mean = Average.
8. Median = Middle.
9. Mode = Most Common.
10. Range = Largest − Smallest.
COMMON MISTAKES
* Forgetting to line up decimals.
* Forgetting to simplify fractions.
* Mixing up mean and median.
* Forgetting to count decimal places in multiplication.
* Forgetting to move BOTH decimals in division.
* Thinking all square roots are rational.
* Forgetting that negative numbers closer to zero are larger.
PRACTICE QUESTIONS
1. Round 45.0193 to the nearest hundredth.
Answer: 45.02
2. Convert 0.36 to a fraction.
Answer: 9/25
3. Convert 3/8 to a decimal.
Answer: 0.375
4. Which is larger: 0.205 or 0.25?
Answer: 0.25
5. Find √64.
Answer: 8
6. Is √5 rational or irrational?
Answer: Irrational
7. Add: 14.563 + 6.29
Answer: 20.853
8. Subtract: 24 − 8.0731
Answer: 15.9269
9. Multiply: 4.8 × 0.13
Answer: 0.624
10. Find the mean of 10, 20, 30.
Answer: 20
31