Fractions
Parts, Sets, and Number Lines
Math workbook
Adding and Subtracting Fractions: Like Units, Common Units, Mixed Numbers
Grades 3–5Level 2
About this book
Make the units match, then add or subtract.
Four modules build fraction addition and subtraction step by step, from like units to mixed numbers. Every module follows the same seven LessonCrest steps, with help that fades as confidence grows.
- Add and subtract fractions with like denominators
- Rename fractions to a common denominator
- Unlike denominators, estimation and simplest form
- Mixed numbers, regrouping and measurement problems
- Answers that explain why, with help for common mistakes
Look inside
What this book covers
Covered
What this book covers: adding and subtracting fractions with like denominators, renaming to common denominators, unlike denominators with estimation checks, and mixed numbers with regrouping in measurement problems.
Not covered
Not covered here: multiplying and dividing fractions, and decimals (they come in later books).
Before you start, you should be able to
- Show that two fractions are equal with a model.
- Find a fraction on a number line.
- Say what the numerator and denominator mean.
- Add and subtract whole numbers.
Things to have
Keep fraction strips or paper strips nearby.
Notice
Pictures in this book are simplified learning models. Check answers with the explanations at the back of the book.
The steps in this book
- Step 1: Get Ready
Check the skills you need before you begin. If something feels tricky, an adult can help you start in the right place.
- Step 2: Learn It
Read a short, clear explanation of the new idea and the words that go with it.
- Step 3: See It
Watch the idea being used, one step at a time, in a worked example.
- Step 4: Try It Together
Practice with prompts and help cues. The help gets smaller as you get stronger.
- Step 5: On Your Own
Practice on your own with different kinds of questions, and explain your thinking.
- Step 6: Look Back
Look back at earlier learning so it stays strong, then check where to go next.
- Step 7: Check and Fix
Check your answers. Each answer explains why, names a common mistake, and shows how to fix it.
What is in the book
The modules
- Module 1: Combine like fractional unitsPages 5–14
- Module 2: Rename to common unitsPages 15–24
- Module 3: Operate with unlike denominatorsPages 25–34
- Module 4: Mixed amounts and applicationsPages 35–44
Contents
- Readiness check, pp. 3–4. Before Module 1. Its table tells you where to start.
- Modules, pp. 5–44
- Checkpoints, pp. 14, 24, 34, 44. The last page of each module.
- Mixed review, pp. 45–48. Questions from across the book, mixed together.
- Exit check, pp. 49–50. A last check across the book.
- Reflect and repair, p. 51
- Try again, p. 52. Fresh questions like those in the exit check.
- Extra practice, pp. 53–54
- Answers and explanations, pp. 55–64. Notes in this part are headed “Why”, “Common mistake”, “Help” and “Look for”.
Other books it mentions
Before this book
After this book
Decimals
Place Value, Compare, and Calculate