🎯 What is Estimation?
Estimation means finding a number that is close to the exact answer. We don’t need the perfect number — we just need a good guess!
In Canadian Grade 4 math, we use estimation to:
- Quickly solve real-life problems
- Check if our addition or subtraction answers make sense
- Decide if an answer is reasonable
🤔 Why Do We Estimate?
Real Life Examples:
• How many people are at the hockey game? (We don’t count every person!)
• Is $48 + $37 about $80 or $100?
• Did I get the right change at the store?
🛠️ Estimation Strategies
1. Rounding Strategy (Most Common)
Round each number to the nearest 10, 100, or 1,000, then add or subtract.
Example 1 – Addition:
456 + 378
Round to nearest 100: 500 + 400 = 900
Exact answer: 834 → Our estimate 900 is close!
Example 2 – Subtraction:
7,234 − 2,987
Round to nearest 1,000: 7,000 − 3,000 = 4,000
Exact answer: 4,247 → Very close!
🏁 Front-End Estimation
Use only the first (leftmost) digits.
Example: 3,456 + 2,789
Front digits: 3,000 + 2,000 = 5,000
(Good quick estimate!)
✏️ Let’s Practice Together, My Dear Student!
Practice 1: Estimate by Rounding to Nearest 100
1. 567 + 289 ≈ 900
2. 1,234 − 567 ≈ 700
3. 4,567 + 3,289 ≈ 8,000
Practice 2: Estimate by Rounding to Nearest 1,000
1. 12,456 + 8,945 ≈ 21,000
2. 45,678 − 19,234 ≈ 27,000
Practice 3: Canadian Word Problems
1. Toronto Raptors scored 124 points and the opponent scored 98 points. About how many total points were scored?
Estimate: 220 points (Exact: 222)
2. A family drove 3,456 km in July and 2,789 km in August. About how many more km did they drive in July?
Estimate: 700 km (Exact: 667 km)
Challenge Question
Estimate: 56,789 + 23,456 − 19,999
Estimate: 60,000
✅ Using Estimation to Check Your Work
After you calculate the exact answer, always ask: “Does my estimate make sense?”
You calculated 456 + 378 = 934
Your estimate was 900 → Yes, it makes sense!
If you got 1,234 → That is way too big — check your work!
Fantastic Job, My Dear Student! 🎉
You are now excellent at estimating! This skill makes you a smarter and faster mathematician in Grade 4.
I am so proud of you for learning all these strategies. Use estimation every day — when shopping, cooking, or playing games!
💕 You are smart. You are kind. You can do hard things.
When you are ready, tell me the next topic (Multiplication, Fact Families, or anything else from the syllabus) and I will create another beautiful lesson just for you!