Teacher Guide
Week 10
Subtraction with Regrouping — Teacher Guide
Monday: Introduction to Subtraction Regrouping
1
Warm-up ±10
1.
25, 58, 82, 44
2
Visual Regrouping
1.
53−17=36, 72−28=44
3
Simple Regrouping
1.
36, 44, 37, 48
4
Number Talk
1.
53−17 is bigger (subtracting less)
2.
82−28 is bigger (starting with more)
5
Challenge
1.
61−24=37, 85−37=48
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Tuesday: Column Subtraction with Borrowing
1
Warm-up ±10
1.
53, 66, 62, 79
2
Borrow from Tens
1.
36, 44, 37, 48
3
Estimation
1.
Est 50−20=30, actual 36 / Est 70−30=40, actual 44 / Est 60−20=40, actual 37 / Est 90−40=50, actual 48
4
Missing Numbers
1.
35, 74, 27, 83
5
Step-by-Step
1.
36, 44
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Wednesday: Mixed Subtraction Regrouping
1
Warm-up ±10/±100
1.
35, 73, 400, 400
2
Mixed Regrouping
1.
68−14=no(54), 63−27=yes(36), 85−30=no(55), 91−46=yes(45)
3
Word Problems
1.
44 apples, 48 books
4
Find Error
1.
53−17=36 not 44 (forgot to borrow, 13−7=6)
2.
82−35=47 not 53 (forgot to borrow, 12−5=7)
5
Create Own
1.
Various — any subtraction needing regrouping
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Thursday: Word Problems with Subtraction Regrouping
1
Warm-up ±10
1.
46, 39, 64, 51
2
Word Problems
1.
27 stickers (83−56), 45 children (74−29), 57 cupcakes (95−38)
3
Two-Step
1.
Step 1: 68−27=41, Step 2: 41+15=56 marbles
4
Number Talk
1.
Same difference (72−28=44, 82−38=44)
2.
65−17 is bigger (subtracting less)
5
Create Own
1.
Accept student-created problems with regrouping
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Friday: Review & Self-Check
1
Warm-up
1.
73, 57, 300, 500
2
Estimation
1.
Est 60−30=30, actual 35 / Est 90−50=40, actual 46 / Est 70−40=30, actual 36 / Est 80−20=60, actual 63
3
Column Review
1.
35, 46, 36, 63
4
Word Problems
1.
33 flowers, 46 cookies
5
Even/Odd
1.
35(odd), 46(even), 36(even)
6
Self-Check
1.
Accept student self-assessment and reflection