Teacher Guide
Week 12
Adding 3 Numbers (to 100) — Teacher Guide
Monday: Adding 3 Numbers
1
Warm-up ±10
1.
52, 65, 46, 78
2
Examples
1.
25+10+20=55, 30+15+5=50
3
Guided Practice
1.
32,62 | 20,45 | 50,58 | 40,60
4
Number Talk
1.
B is easier (15+5=20) | Same sum either way (commutative)
5
Word Problem
1.
12+8+15=35 shells
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Tuesday: Group Friendly Numbers
1
Warm-up
1.
63, 58, 101, 64
2
Strategy
1.
18+32=50, +25=75 | 43+7=50, +29=79
3
Friendly Pair
1.
25+15=40, +38=78 | 6+34=40, +22=62 | 28+12=40, +40=80 | 53+7=60, +19=79
4
Word Problems
1.
18+12+27=57 kids | 24+6+35=65 flowers
2.
Two Ways: 16+24+8=48 both ways (e.g., 16+24=40 first, or 24+8=32 first — order doesn't change the sum)
5
Make 100
1.
Many answers: 40+30+30, 50+25+25, etc.
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Wednesday: Estimating 3-Number Sums
1
Warm-up
1.
57, 44, 45, 33
2
Estimation
1.
Est 30+10+30=70, actual 66 | Est 40+20+40=100, actual 97 | Est 50+30+20=100, actual 99 | Est 30+50+10=90, actual 93
3
Practice
1.
70, 80, 69, 78, 85, 92
4
Missing Numbers
1.
15+20+20=55 | 20+30+25=75
5
Word Problems
1.
18+22+15=55 books | 36+24+20=80 people
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Thursday: Application & Challenges
1
Warm-up
1.
71, 53, 500, 200
2
Real-World Problems
1.
14+8+23=45 pets | 45+25+30=100 pounds | 38+22+40=100 meters
3
Number Talk
1.
B bigger (25+20+35 > 15+25+30) | Same (all 90)
4
Even/Odd
1.
70(even), 69(odd), 90(even)
5
Create Own
1.
Accept student-created problems
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Friday: Review & Self-Check
1
Warm-up
1.
66, 62, 400, 400
2
Estimation
1.
Est 30+30+20=80, actual 79 | Est 50+20+30=100, actual 94
3
Review
1.
80, 70, 79, 100
4
Word Problem
1.
26+14+20=60 books
5
Self-Check
1.
Accept student self-assessment and reflection