#14
Regroup to Tens
1
5 2 7
+ 2 4 6
7 7 3
#15
Regroup Both!
1 1
1 8 9
+ 6 5 3
8 4 2
#16
Regroup Both!
1 1
4 7 6
+ 2 5 8
7 3 4
#17
Regroup Both!
1 1
3 8 5
+ 2 9 7
6 8 2
#18
Regroup Both!
1 1
5 4 9
+ 2 8 4
8 3 3
#19
Regroup Both!
1 1
6 3 8
+ 1 8 5
8 2 3
#20
Regroup Both!
1 1
4 5 9
+ 3 7 6
8 3 5
Error: "Forgetting the Carried 1" Student adds \( 4 + 8 = 12 \) in tens column, ignoring the carried 1 on top (producing 2 instead of 3).
Fix: Have student circle the carry box in yellow highlighter and add it first!
Error: "Carrying to Wrong Column" Student adds ones and carries all the way to the hundreds box.
Fix: Use physical arrow pointers or touch points moving exactly one neighbor left.
Teacher Key • Monday Addition Page 2 of 2 (Questions 11–20)
6
5
Page 1 of 3 • Next: Borrowing in Both Place Values (Double Regrouping)
Wednesday Resource Math • Section B
Questions 7 to 13
Modeled Example 2
H
T
O
BORROW
4
12
13
5
3
3
-
2
7
6
2
5
7
Step 1 (Ones): 3 - 6 needs a borrow. Cross 3 tens -> becomes 2 tens. Ones becomes 13. \( 13 - 6 = 7 \).
Step 2 (Tens): Now we have 2 tens minus 7! Needs a borrow too! Cross 5 hundreds -> becomes 4. Tens becomes 12. \( 12 - 7 = 5 \).
Step 3 (Hundreds): 4 - 2 = 2. Final difference: 257.
#7 Double Regroup
RENAME
6
2
4
-
2
7
8
#8 Double Regroup
RENAME
7
4
3
-
3
6
9
#9 Double Regroup
RENAME
5
1
2
-
2
8
7
#10 Double Regroup
RENAME
8
3
5
-
4
6
8
#11 Double Regroup
RENAME
6
5
4
-
2
8
9
#12 Double Regroup
RENAME
7
2
1
-
3
5
6
#13 Double Regroup
RENAME
9
4
2
-
5
8
7
💡
"Never subtract upside-down! If top digit is smaller, borrow from your left neighbor before you subtract!"
Page 2 of 3 • Next: Borrowing Across Zeroes (Problems 14 to 20)
Wednesday Resource Math • Section C
Questions 14 to 20
Modeled Example 3
H
T
O
BORROW
4
9
12
5
0
2
-
2
6
7
2
3
5
Zero has nothing to give! Ones needs to borrow, but tens has 0.
Go to Hundreds: Cross out 5 hundreds -> becomes 4. Tens becomes 10.
Now Tens can share: Cross out 10 tens -> becomes 9. Ones becomes 12.
Subtract: 12 - 7 = 5, 9 - 6 = 3, 4 - 2 = 2. Difference: 235.
#14 Across Zero
RENAME
5
0
4
-
2
3
8
#15 Across Zero
RENAME
6
0
3
-
2
7
5
#16 Double Zero
RENAME
7
0
0
-
3
4
6
#17 Double Zero
RENAME
4
0
0
-
1
8
3
#18 Across Zero
RENAME
8
0
2
-
4
5
7
#19 Across Zero
RENAME
9
0
5
-
3
6
8
#20 Double Zero
RENAME
5
0
0
-
2
7
4
✓
You mastered borrowing once, borrowing twice, and borrowing across zeroes!
⭐ All 20 Wednesday problems complete!
Page 3 of 3 • Wednesday Subtraction Packet Complete
- 5 8 7
3 5 5
#14
Across Zero
4 9 14
5 0 4
- 2 3 8
2 6 6
#15
Across Zero
5 9 13
6 0 3
- 2 7 5
3 2 8
#16
Double Zero
6 9 10
7 0 0
- 3 4 6
3 5 4
#17
Double Zero
3 9 10
4 0 0
- 1 8 3
2 1 7
#18
Across Zero
7 9 12
8 0 2
- 4 5 7
3 4 5
#19
Across Zero
8 9 15
9 0 5
- 3 6 8
5 3 7
#20
Double Zero
4 9 10
5 0 0
- 2 7 4
2 2 6
Error: "The Magician's Ten" Student turns 0 directly into 10 without taking anything from hundreds, then gives to ones.
Cure: Physically model with base-ten blocks. You cannot break a ten rod that doesn't exist! First break a hundred flat into 10 rods.
Strategy: "The Box Trick" (50 becomes 49) For numbers like 504, have student draw a box around "50". 50 tens minus 1 ten is 49 tens! Write 4 in hundreds, 9 in tens, 14 in ones.
Resource students love this shortcut because it eliminates double slashes!
Teacher Key • Wednesday Subtraction Page 2 of 2 (Questions 11–20)
2
4
7
Page 1 of 3 • Turn page for questions 7 to 13
Thursday Resource Math • Mixed Set 2
Questions 7 to 13
#7 HUNDREDS • TENS • ONES
H
T
O
RENAME
4
2
7
-
1
6
9
#8 HUNDREDS • TENS • ONES
H
T
O
RENAME
7
0
3
-
3
8
5
#9 HUNDREDS • TENS • ONES
H
T
O
RENAME
8
4
6
-
5
1
8
#10 HUNDREDS • TENS • ONES
H
T
O
RENAME
9
0
0
-
4
5
2
#11 HUNDREDS • TENS • ONES
H
T
O
RENAME
5
3
1
-
2
7
4
#12 HUNDREDS • TENS • ONES
H
T
O
RENAME
6
8
4
-
2
9
1
#13 HUNDREDS • TENS • ONES
H
T
O
RENAME
8
0
7
-
3
4
9
🔍
Want to know if your answer is 100% correct? Add your answer to the bottom number! If you get the top number, you are a master!
Answer + Bottom = Top!
Page 2 of 3 • Final mixed showdown on page 3
Thursday Resource Math • Final Sprint
Questions 14 to 20
#14 HUNDREDS • TENS • ONES
H
T
O
RENAME
7
5
2
-
3
8
6
#15 HUNDREDS • TENS • ONES
H
T
O
RENAME
4
0
0
-
1
6
7
#16 HUNDREDS • TENS • ONES
H
T
O
RENAME
6
7
5
-
2
3
8
#17 HUNDREDS • TENS • ONES
H
T
O
RENAME
9
2
3
-
5
6
7
#18 HUNDREDS • TENS • ONES
H
T
O
RENAME
5
0
6
-
2
8
9
#19 HUNDREDS • TENS • ONES
H
T
O
RENAME
8
3
4
-
4
7
8
#20 HUNDREDS • TENS • ONES
H
T
O
RENAME
7
0
0
-
2
8
5
★
I inspected each column I borrowed before subtracting I checked my answers
🏆 All 20 Thursday review problems finished!
Page 3 of 3 • Thursday Subtraction Packet Complete
Double Borrow
6 14 12
7 5 2
- 3 8 6
3 6 6
#15
Double Zero
3 9 10
4 0 0
- 1 6 7
2 3 3
#16
Borrow Once (Ones)
6 15
6 7 5
- 2 3 8
4 3 7
#17
Double Borrow
8 11 13
9 2 3
- 5 6 7
3 5 6
#18
Across Zero
4 9 16
5 0 6
- 2 8 9
2 1 7
#19
Double Borrow
7 12 14
8 3 4
- 4 7 8
3 5 6
#20
Double Zero
6 9 10
7 0 0
- 2 8 5
4 1 5
Single Borrow Struggles Missed Q2, Q5, Q9, Q12, or Q16: Student is not yet fluent with identifying when the bottom digit is larger. Revisit comparison symbols (>, <).
Double Borrow Struggles Missed Q1, Q4, Q7, Q11, Q14, Q17, Q19: Student forgets that the tens digit was already reduced by 1 when borrowing for the ones. Emphasize slashing immediately.
Zero Borrow Struggles Missed Q3, Q6, Q8, Q10, Q13, Q15, Q18, Q20: Student struggles with the multi-step chain across 0. Practice the "Box Trick" (treating 50 as 49 tens).
Teacher Key • Thursday Subtraction Review Page 2 of 2 (Questions 11–20)
1
7
6
#8 HUNDREDS • TENS • ONES
H
T
O
BOX
2
8
4
4
5
8
#9 HUNDREDS • TENS • ONES
H
T
O
BOX
9
1
5
-
4
6
8
#10 HUNDREDS • TENS • ONES
H
T
O
BOX
6
3
7
1
9
5
#11 HUNDREDS • TENS • ONES
H
T
O
BOX
7
6
3
-
2
9
1
#12 HUNDREDS • TENS • ONES
H
T
O
BOX
3
8
5
4
7
8
#13 HUNDREDS • TENS • ONES
H
T
O
BOX
6
0
0
-
2
4
7
🎯
Plus (+) means join: answer gets BIGGER.
Minus (-) means take away: answer gets SMALLER.
Check: Does my answer make sense?
Page 2 of 3 • Final sprint on page 3
Early Finisher Challenge • Final Sprint
Questions 14 to 20
#14 HUNDREDS • TENS • ONES
H
T
O
BOX
8
3
2
-
3
5
9
#15 HUNDREDS • TENS • ONES
H
T
O
BOX
4
5
9
2
8
6
#16 HUNDREDS • TENS • ONES
H
T
O
BOX
7
0
4
-
3
8
6
#17 HUNDREDS • TENS • ONES
H
T
O
BOX
5
6
8
2
7
4
#18 HUNDREDS • TENS • ONES
H
T
O
BOX
9
4
6
-
4
8
2
#19 HUNDREDS • TENS • ONES
H
T
O
BOX
3
7
8
4
9
5
#20 HUNDREDS • TENS • ONES
H
T
O
BOX
8
0
0
-
4
6
3
★
I checked every plus & minus sign I carried for addition & borrowed for subtraction I worked carefully to the end
🏆 Bonus Challenge Mastered!
Page 3 of 3 • Early Finisher Packet Complete
#12
ADD (+)
Regroup Both
1 1
3 8 5
+ 4 7 8
8 6 3
#13
SUB (-)
Double Zero
5 9 10
6 0 0
- 2 4 7
3 5 3
#14
SUB (-)
Double Borrow
7 12 12
8 3 2
- 3 5 9
4 7 3
#15
ADD (+)
Regroup Both
1 1
4 5 9
+ 2 8 6
7 4 5
#16
SUB (-)
Across Zero
6 9 14
7 0 4
- 3 8 6
3 1 8
#17
ADD (+)
Regroup Both
1 1
5 6 8
+ 2 7 4
8 4 2
#18
SUB (-)
Borrow Once (Tens)
8 14
9 4 6
- 4 8 2
4 6 4
#19
ADD (+)
Regroup Both
1 1
3 7 8
+ 4 9 5
8 7 3
#20
SUB (-)
Double Zero
7 9 10
8 0 0
- 4 6 3
3 3 7
Inverse Operation Check Have the student select any 3 subtraction problems and check them with addition on the back (Difference + Subtrahend = Minuend).
Student Problem Designer Ask the student to create their own 3-digit problem that requires borrowing across a zero, then solve it with base-ten stamps or grid sketches.
Teacher Key • Fast Finisher Blended Challenge Page 2 of 2 (Questions 11–20)
