This week
Lessons 41, 42, 43, 44, & 45
STILLWATER CROSSING · THE COURSE NOTES · BRIDGE MATH 5/6
Week 9 · The Least Common Denominator
Papers
Quiz 4 in class · Last test graded and signed at home
Method
No calculators, ever · show every step
Note-Taking Tip: Use a color-coding system when reviewing your notes. For example, blue for definitions, yellow for steps, orange for difficult concepts or green for examples.
Instructional notes
Least Common Denominator (LCD) The LCD is the least common multiple (LCM) between two or more denominators.
To compare fractions with different denominators: • Find the LCD • Make equivalent fractions using the LCD • Compare the numerators
Example
Find the LCD and then compare the fractions.
Fraction Multiples of Denominators LCM LCD 5 6, 12, 18, 24, 30, 36 18 18 6
7 9, 18, 27, 36, 45, 54 9
5 15 14 7 = ˃ = 6 18 18 9
Practice
Find the LCD and then compare the fractions.
Fraction Multiples of Denominators LCM LCD
6
4 8 5 1 = ˃ = 15 30 30 6
Fraction Multiples of Denominators LCM LCD 3 5, 10, 15, 20, 25, 30, 35, 40 20 20 5
= ˃ = 5 20 20 20
Instructional notes
Adding/Subtracting with Common Denominators • Add or subtract the numerators • Keep the denominator the same • Reduce or simplify if needed
If adding or subtracting mixed numbers, add or subtract the fractions before the whole numbers.
Example
Find the sum or difference. Simplify when possible.
-5
Practice
Find the sum or difference. Simplify when possible.
3 29 5
Instructional notes
A pictograph is a graph that uses pictures to show data and make comparisons. Use Work text page 79 or create a class pictograph.
Instructional notes
Sums Containing Improper Fractions When a sum contains an improper fraction, we need to change the improper fraction to a mixed number or whole number.
To simplify a sum containing an improper fraction: • Change the improper fraction • Add to the whole number already in the sum__ • Simplify if needed
Example
Find the sum. Simplify when possible.
Practice
Find the sum. Simplify when possible.
Homework this week
| Work-text | Lesson 41 | Lesson 42 | Lesson 43 | Lesson 44 |
|---|---|---|---|---|
| Speed drill | 41 | 42 | 43 | 45 |
Terms on the record
| Term | Meaning |
|---|---|
| least | The LCD is the least common multiple (LCM) between two or more |
| common | The LCD is the least common multiple (LCM) between two or more |
| multiple | The LCD is the least common multiple (LCM) between two or more |
| pictograph | A pictograph is a graph that uses pictures to show data and make |
STILLWATER CROSSING // BRIDGE MATH // PENUMBRA · steady on