Expedition Notes Updated Document Expedition Notes
Guided Note-Taking for Estimation Edge
Name:
Date:
The "Why" of Estimation
1. Speed
Get an answer when you don't need the number.
2. Reasonableness
Check to see if your answer !
Rounding Road
Round 472 to the nearest hundred:
400
450
500
472 is closer to , so we round up!
Compatible Numbers
"Friendly" numbers that work well together in your .
Example: 152 + 48 → 150 +
Example: 24 + 77 → 25 +
Guided Practice Expedition
Ex 1: Product (29 × 19)
Estimate is ( greater / less ) than actual because:
Ex 2: Money Sum
$8.95, $7.23, $11.42, $6.89
Estimated Total: $
Ex 3: Perimeter (78mm × 31mm)
Show Your Work Area
Rounding: 78 → | 31 →
Ex 4: Animal Weight Difference
Porpoise (103 lbs) vs. Cat (14 lbs)
Difference: lbs more
Mission Checklist:
Accurate Rounding
Friendly Pairs
Reasonable Estimates
Estimation Edge Slides Estimation Edge
Mastering the Art of the "Quick Guess"
4th GRADE MATH
Why Estimate?
Speed
Get an answer quickly when you don't need the exact number.
Reasonableness
Check if your final answer makes sense!
"I'm at the store with $20. If I buy a game for $12.89 and a snack for $4.15, do I have enough?"
Rounding Road
Round to the nearest Hundred :
400
450
500
472
Since 472 is closer to 500 than 400,
Compatible Numbers
Compatible numbers are pairs of numbers that are easy to add, subtract, multiply, or divide mentally.
The Goal:
Find numbers that make tens or hundreds !
152 + 48 150 + 50
24 + 77 25 + 75
Product Predictions
Example 1:
Estimate the product of 29 and 19 .
29 × 19
Rounding to Tens:
30 × 20 = 600
Think It Through:
Is the estimate greater than or less than the actual? Greater! Because we rounded both numbers up.
Supply Run
Example 2: Estimate the total to the nearest dollar.
Flashlight
$8.95
→ $9
Snacks
$7.23
→ $7
First Aid
$11.42
→ $11
Batteries
$6.89
→ $7
9 + 7 + 11 + 7 = $34
Map Measure
Example 3: Estimate the perimeter.
Round length and width to the nearest **ten millimeter** before calculating.
Round the dimensions:
78 mm → 80 mm
31 mm → 30 mm
78 mm 31 mm
P = 2(L + W)
2(80 + 30) = 220 mm
Wildlife Weight
Example 4: A Cat weighs 14 lbs and a Porpoise weighs 103 lbs. About how many more lbs does a porpoise weigh?
Cat
14 lbs → 10 lbs
Porpoise
103 lbs → 100 lbs
100 - 10 = 90 lbs more
Ready for the Expedition?
Round accurately
Find friendly numbers
Solve mentally
Let's start the Rounding Road worksheet!
Rounding Road Worksheet Rounding Road
Estimation Expedition: Mission 1
Name:
Date:
Mission Briefing
To estimate sums and differences, round each number to the place value requested. Use the number lines below to help you see which "landmark" number is closer to your hiker!
Round to the Nearest Ten
1. Estimate the sum: 43 + 28
Example: Round each number first
Round 43:
40
45
50
43
Round 28:
20
25
30
28
=
2. Estimate the difference: 86 - 34
Round 86:
80
90
Round 34:
30
40
-
=
Round to the Nearest Hundred
3. Estimate the sum: 472 + 319
Round 472:
400
450
500
Round 319:
300
350
400
=
4. Estimate the difference: 654 - 281
Round 654:
600
700
Round 281:
200
300
-
=
Summit Challenge: Word Problem
The base camp of Mount Math is at 1,248 feet . The peak is at 4,892 feet . About how many feet must a hiker climb to get from base camp to the peak? Round to the nearest thousand .
Rounding 4,892 to nearest 1,000:
Rounding 1,248 to nearest 1,000:
Estimated Climb:
Friendly Pairs Activity Friendly Pairs
Estimation Expedition: Mission 2
Name:
Mission: Compatible Connections
Sometimes rounding to the nearest ten isn't the fastest way. Compatible numbers are "friendly" numbers that work well together in your head. Cut out the gear tags at the bottom and match them to the correct trail problem!
1
148 + 52
Glue Compatible Match Here
Glue Answer Tag Here
2
26 + 74
Glue Compatible Match Here
Glue Answer Tag Here
3
324 - 98
Glue Compatible Match Here
Glue Answer Tag Here
4
173 + 228
Glue Compatible Match Here
Glue Answer Tag Here
Cut Along Dotted Lines
150 + 50
25 + 75
325 - 100
175 + 225
200
100
225
400
Estimation Edge Answer Key Teacher Answer Key
Estimation Edge Lesson Suite
Internal Use Only
Slide Examples (Guided Practice)
Example 1: 29 × 19 → 30 × 20 = 600. (Greater than actual because both rounded up).
Example 2: $9 + $7 + $11 + $7 = $34.
Example 3: 2 × (80 + 30) = 220 mm.
Example 4: 100 lbs - 10 lbs = 90 lbs more.
Rounding Road Worksheet
1. 43 + 28 (Ten)
40 + 30 = 70
2. 86 - 34 (Ten)
90 - 30 = 60
3. 472 + 319 (Hundred)
500 + 300 = 800
4. 654 - 281 (Hundred)
700 - 300 = 400
Friendly Pairs Activity
1. 148 + 52 → 150 + 50 = 200
2. 26 + 74 → 25 + 75 = 100
3. 324 - 98 → 325 - 100 = 225
4. 173 + 228 → 175 + 225 = 400
Expedition Challenges
1. Total Cost (Hundred)
300 + 100 = $400
2. Difference (Ten)
440 - 270 = 170 miles
3. Trees (Compatible)
150 + 50 = 200 trees
4. Money Left (Hundred)
1,000 - 700 = $300
Teaching Tip
Use the slide examples to model mathematical reasoning . For Example 1, emphasize that rounding up both factors creates an "overestimate." This strategy helps students develop number sense beyond just following a rounding rule.
Estimation Expedition Challenges Expedition Challenges
Estimation Expedition: Mission 3
Name:
Date:
Word Problem Mission
Use your estimation skills to solve these real-world mountain scenarios. Remember, an estimation doesn't have to be exact, but it must be reasonable! Look for clues on whether to round to the nearest ten, hundred, or use compatible numbers.
1
A hiking group needs to buy supplies. A heavy-duty tent costs $287 and a portable stove costs $112 . Give an estimation of the total cost by rounding to the nearest hundred .
Round $287:
Round $112:
Show your work:
Estimated Total: $__________________
2
The "Eagle Trail" is 438 miles long. The "Bear Path" is 274 miles long. What is the estimation of the difference in length between the two trails? Round to the nearest ten .
Round 438:
Round 274:
Show your work:
Estimated Difference: __________________ miles
3
A park ranger counted 147 pine trees in one valley and 48 pine trees in another. Use compatible numbers to find an estimation of how many pine trees there are in total.
Tip: Use numbers that end in 50 or 00 to make it easy!
Show your work:
Estimated Trees: __________________
4
A team of climbers has $1,000 for their expedition. They spent $682 on climbing gear. Provide an estimation of how much money they have left by rounding to the nearest hundred .
Show your work:
Estimated Money Left: $__________________
Is your estimation enough to buy a $200 emergency kit?
Navigator's Log
In your own words, why is estimation helpful when planning a big mountain trip?
Summit Scramble Game Summit Scramble
Partner Strategy Game: Estimation Expedition
2 PLAYERS
MISSION 4
How to Play
Place your markers (coins or erasers) at Base Camp .
On your turn, draw a Challenge Card .
Your partner must estimate the answer using rounding or compatible numbers.
If the estimate is reasonable (within 10 of the teacher key's estimate), you move 1 space!
Land on a Shortcut ? Solve an extra challenge to jump ahead!
The Goal
Work together to reach the Peak Performance Summit before the storm clouds roll in! This is a cooperative race—both climbers must reach the top to win.
Base Camp
1
2
SHORTCUT
3
4
SHORTCUT
5
Peak Performance
Cut cards for your deck
Addition
342 + 189
Subtraction
827 - 394
Money
$12.45 + $8.12
Compatible
148 + 52
Hundreds
612 + 288
Distance
456 - 123
Shortcut
Round 1,284 to nearest 1,000
Wildlife
15 lbs + 103 lbs
Expedition Notes Sheet Expedition Notes
Guided Guided Note-Taking: Estimation Edge Slides
Name:
Date:
The "Why" of Estimation
1. Speed
Get an answer ________________ when you don't need the ________________ number.
2. Reasonableness
Check to see if your answer ________________ ________________!
Rounding Road
Round 472 to the nearest hundred:
400
450
500
472 is closer to ___________, so we round up!
Compatible Numbers
"Friendly" numbers that work well together in your ________________.
Example: 152 + 48 → 150 + ________
Example: 24 + 77 → 25 + ________
Guided Practice Expedition
Example 1: Product of 29 and 19
Work: ________________ × ________________ = ________________
Our estimate is ( CIRCLE ONE: greater than / less than ) the actual product because...
Example 2: Money Sum
$8.95, $7.23, $11.42, $6.89
Work: ____ + ____ + ____ + ____ = $________
Example 3: Perimeter (78mm by 31mm)
Round Length: ________ mm
Round Width: ________ mm
P = 2 × ( ____ + ____ ) = ________ mm
Example 4: Wildlife Weight
Porpoise (103 lbs) vs. Cat (14 lbs)
Porpoise rounds to: ________ lbs
Difference: ________ - ________ = ________ lbs more
Mission Checklist:
Accurate Rounding
Friendly Pairs
Reasonable Estimates
Expedition Notes Sheet Revised Expedition Notes
Guided Note-Taking: Estimation Edge Slides
Name:
Date:
The "Why" of Estimation
1. Speed
Get an answer ________________ when you don't need the ________________ number.
2. Reasonableness
Check to see if your answer ________________ ________________!
Rounding Road
Round 472 to the nearest hundred:
400
450
500
472 is closer to __________, so we round up!
Compatible Numbers
"Friendly" numbers that work well together in your ________________.
Example: 152 + 48 → 150 + ________
Example: 24 + 77 → 25 + ________
Guided Practice Expedition
Ex 1: Product (29 × 19)
The estimate is ( greater / less ) than actual because:
Ex 2: Money Sum
$8.95, $7.23, $11.42, $6.89
Estimated Total: $__________________
Ex 3: Perimeter (78mm × 31mm)
Sketch Area
78 → ______ | 31 → ______
Perimeter: ________________ mm
Ex 4: Comparison
Porpoise (103 lbs) vs. Cat (14 lbs)
Difference: ________ - ________ = ________ lbs more
MISSION CHECKLIST:
Accurate Rounding
Friendly Pairs
Reasonable Estimates
Expedition Notes Sheet Revised Final Expedition Notes
Guided Note-Taking for Estimation Edge
Name:
Date:
The "Why" of Estimation
1. Speed
Get an answer ________________ when you don't need the ________________ number.
2. Reasonableness
Check to see if your answer ________________ ________________!
Rounding Road
Round 472 to the nearest hundred:
400
450
500
472 is closer to __________ , so we round up!
Compatible Numbers
"Friendly" numbers that work well together in your ________________ .
Example: 152 + 48 → 150 + ________
Example: 24 + 77 → 25 + ________
Guided Practice Expedition
Ex 1: Product (29 × 19)
The estimate is ( greater / less ) than actual because: _________________________________________
Ex 2: Money Sum
$8.95, $7.23, $11.42, $6.89
Estimated Total: $________________
Ex 3: Perimeter (78mm × 31mm)
Sketch & Calculation
Rounding: 78 → ______ | 31 → ______
Ex 4: Animal Weight Difference
Porpoise (103 lbs) vs. Cat (14 lbs)
Difference: ________________ lbs more
Mission Checklist:
Accurate Rounding
Friendly Pairs
Reasonable Estimates
Estimation Edge Lesson Plan Estimation Edge
Teacher Facilitation Guide
GRADE 4 | MATH
DURATION: 60-75 MINUTES
Mission Objective
Students will master the art of estimation by rounding to the nearest ten, hundred, and thousand, as well as identifying compatible numbers to solve multi-step addition, subtraction, and simple multiplication problems mentally.
Key Standards (CCSS)
4.NBT.A.3: Use place value understanding to round multi-digit whole numbers to any place. 4.OA.A.3: Assess the reasonableness of answers using mental computation and estimation strategies.
Gear List
Estimation Edge Slides
Expedition Notes Sheet
Rounding Road Worksheet
Friendly Pairs Activity
Expedition Challenges
Summit Scramble Game
Expedition Timeline
1
Direct Instruction & Notes (15-20 Min)
Present the Estimation Edge Slides . Have students follow along using the Expedition Notes Sheet .
Slide 1-4: Define estimation, rounding, and compatible numbers.
Slide 5: Teacher Modeling - Explain why rounding up both factors creates an overestimate.
Slide 6-8: Guided practice for money, perimeter, and subtraction.
2
Guided Practice: Rounding Road (15 Min)
Transition to the Rounding Road Worksheet . Complete the first two problems together, focusing on the visual number line. This builds the conceptual bridge between place value and the "closeness" of estimates.
3
Cooperative Learning: Summit Scramble (15-20 Min)
Students pair up for the Summit Scramble Game .
Teacher Tip: Move around the room to verify that students are using mental math strategies. If a pair is stuck, suggest a "Friendly Number" (compatible number) to help them move forward.
4
Independent Mission: Expedition Challenges (15 Min)
Students complete the Expedition Challenges word problem sheet independently. Use this as a formative assessment to check who is ready for multi-digit estimation.
For Climbers (Challenge)
Ask students to find the exact difference between their estimate and the actual answer. Who can get the "closest" estimate without calculating the whole problem first?
Support Crew (Scaffolding)
Backpack Weigh-In Hook Anticipatory Set
3-5 Minute Warm-Up
BACKPACK WEIGH-IN
The 30-Second Trail Challenge
Pro Tent
27 lbs
Sleep Bag
12 lbs
Water Jug
19 lbs
MISSION QUESTION:
Is the total weight more or less than 50 lbs?
More
Less
No Pencils
Quick Guess
30 Seconds
Teacher Quick Guide
"Climbers! Before we hit the trail, we need to check our gear. Look at these three items. Don't write anything down—just use your 'internal calculator'. On the count of three, show me a thumbs up if you think this backpack is heavier than 50 pounds, or thumbs down if it's lighter. 3... 2... 1... Show me!"
