Double Digit Duels Teacher Guide Reveal Math • Grade 2 Teacher Guide
Double Digit Duels
Topic: Fluency & Algorithms for Two-Digit Addition & Subtraction
Pacing 60 Minutes
Standards 2.NBT.B.5, 2.NBT.B.9
Focus Strategies Regrouping & Place Value
Learning Objectives
Solve 2-digit addition and subtraction equations with regrouping.
Model regrouping using base-ten visual representations.
Explain the steps of the standard algorithm using place value language.
Key Vocabulary
• Regrouping (Trading)
• Algorithm
• Ones & Tens Place
• Sum & Difference
Part 1 Launch: The 10-Ones Trade (10 Mins)
Begin by displaying 14 loose ones blocks on the board. Ask students: "Can we make a neat stack of ten?" Demonstrate physically or digitally grouping 10 ones and trading them for 1 tens rod, leaving 4 ones behind.
Teacher Script: "In our base-ten country, the ones place is a tiny house. Only 9 people can fit! As soon as we get 10, they must hold hands, pack their bags, and move next door into the Tens Tower as exactly ONE ten."
Part 2 Guided Instruction: Addition with Regrouping (15 Mins)
Model the problem: 38 + 25 on the board using both base-ten drawings and the standard vertical algorithm side-by-side.
Step-by-Step Modeling
Add the ones first: 8 + 5 = 13 ones.
Ask: "Can we regroup?" Yes! 13 is 1 ten and 3 ones.
Write the 3 in the ones place, write the tiny regrouped 1 above the tens column.
Add the tens columns: 1 + 3 + 2 = 6 tens. Total sum: 63.
Guiding Questions
"Where do we always start adding? Why can't we write '13' down in the ones box? Where does that ten go?"
Reinforce writing the "carried" ten on top.
Digit Dynamics Curriculum • Double Digit Duels Page 1 of 2
Lesson 1: Double Digit Duels Substitutions & Pitfalls
Part 3 Guided Instruction: Subtraction with Regrouping (15 Mins)
Model the subtraction problem: 52 - 27 . Guide students in verifying whether subtraction is possible in the ones column without breaking a ten.
Subtle Borrowing Steps
Look at the ones place: 2 - 7. Ask: "Do we have more on top or more on the floor?"
More on the floor! We must borrow or "regroup".
Go to the tens column. Cross out the 5 tens and make it 4 tens.
Bring 10 ones over to the ones column. The 2 ones becomes 12 ones.
Now subtract: 12 - 7 = 5 ones, and 4 - 2 = 2 tens. Result: 25.
The Magic Subtraction Rhyme
"More on top? No need to stop!
Have students chant this three times before practicing on their whiteboards to internalize the rule.
Common Misconceptions & Corrections
A.
The "Flip-Over" Subtraction Error: Students subtract the smaller top number from the larger bottom number (e.g. for 52 - 27, doing 7 - 2 = 5ones, returning 35).
B.
The "Ghost Ten" Addition Error: Forgetting to add the regrouped ten in the tens column.
Differentiation & Support Strategies
Tier 1: Support
Allow student to work with concrete base-ten blocks side-by-side with every standard algorithm problem on the practice sheet. Avoid dry-erase drawings until concrete understanding is firm.
Tier 2: On-Level
Students draw lines and blocks on the grid paper. They solve independently but work with partners to describe their steps using correct place value terms.
Tier 3: Challenge
Have students write simple word problems containing missing sub-addends or multi-step subtraction, requiring them to analyze which operations are necessary.
Exit Ticket Quick Check (10 Mins)
Distribute the 3-question Exit Ticket. Scan answers for correct regrouping notation. Focus on students who solved addition but struggled with subtraction.
Digit Dynamics Curriculum • Double Digit Duels Page 2 of 2
Double Digit Duels Practice Worksheet Digit Dynamics • Lesson 1 Practice
Double Digit Duels
Practice standard algorithms for two-digit addition & subtraction with regrouping.
Name:
Date:
Addition Duel Checklist: Always start in the Ones Place ! If your ones add up to 10 or more , regroup 1 ten over to the Tens column, and write the leftovers in the ones place.
Round 1 Addition Showdown: Add with Regrouping
47 + 25
Write your final answer below.
T
O
4
7
2
5
39 + 18
Write your final answer below.
T
O
3
9
1
8
56 + 26
Write your final answer below.
T
O
5
6
2
6
68 + 14
Write your final answer below.
T
O
6
8
1
4
Digit Dynamics Curriculum • Double Digit Duels Page 1 of 2
Digit Dynamics • Lesson 1 Practice
Subtraction Duel Checklist: Look at the ones place. If the bottom number is bigger, you must regroup ! Cross off 1 ten from your tens place, add 10 ones to your ones column, and then subtract.
Round 2 Subtraction Showdown: Subtract with Regrouping
62 - 38
Write your final answer below.
T
O
6
2
-
3
8
83 - 45
Write your final answer below.
T
O
8
3
-
4
5
74 - 29
Write your final answer below.
T
O
Double Digit Duels Exit Ticket Digit Dynamics • Quick Check
Double Digit Duels Exit Ticket
Show what you know about two-digit addition & subtraction!
Name:
Date:
Solve the problems below carefully. Remember to show your regrouping symbols in the columns!
Problem 1
Solve with Addition:
Add the ones, regroup if needed, then add the tens column.
58 + 27 =
T
O
5
8
2
7
Problem 2
Solve with Subtraction:
Look at the ones first. More on the floor? Go next door!
73 - 46 =
T
O
7
3
-
4
6
Problem 3
Explain Your Math Thinking
Maya is solving the addition problem: 45 + 38 . Her ones added up to 13ones . She wrote down the 3 in the ones column, and put a tiny 1 above the tens column.
Digit Dynamics Curriculum • Double Digit Duels Exit Ticket • Page 1 of 1
Triple Digit Treasure Teacher Guide Reveal Math • Grade 2 Teacher Guide
Triple Digit Treasure
Topic: Three-Digit Place Value, Expanded Form & Comparisons
Pacing 60 Minutes
Standards 2.NBT.A.1, 2.NBT.A.3, 2.NBT.A.4
Focus Strategies Hundreds, Tens, Ones Chart
Learning Objectives
Identify hundreds, tens, and ones in a 3-digit number.
Write 3-digit numbers in standard, expanded, and word forms.
Compare two 3-digit numbers using relational symbols (<, >, =).
Key Vocabulary
• Hundreds Block
• Standard Form
• Expanded Form
• Relational Symbols
Part 1 Launch: Trading up to the Hundred Flat (10 Mins)
Gather students. Hold up 10 tens rods . Count together: "10, 20, 30, 40, 50, 60, 70, 80, 90, 100!" Show that stacking 10 tens rods matches exactly with 1 flat hundreds grid.
Teacher Script: "We know that ten ones make one ten. Today, we have a bigger math trade! Ten of our tens rods are going to fuse together into a giant, flat hundreds plate. This is our gold treasure chest!"
Part 2 Guided Instruction: Representing 3-Digits (15 Mins)
Model drawing the number 345 on the board. Create 3 large boxes (Hundreds), 4 tall rods (Tens), and 5 small dots (Ones).
The Three Forms of a Number
Standard Form: 345 (The plain number)Expanded Form: 300 + 40 + 5 (Showing the secret values of each digit)Word Form: "three hundred forty-five"
Guiding Questions
"What does the '4' in 345 stand for? Is it worth 4, or 40? Why is expanded form like stretching an accordion?"
Reinforce that 0 acts as a placeholder (e.g. 305).
Digit Dynamics Curriculum • Triple Digit Treasure Page 1 of 2
Lesson 2: Triple Digit Treasure Comparisons & Practice
Part 3 Guided Instruction: Comparing 3-Digit Values (15 Mins)
Teach students how to compare 427 and 452 using standard inequality signs. Explain how to write these inside a vertical comparison card.
The Comparison Checklist
Look at the Hundreds column first: 4 = 4 (It is a tie!).
Since they are tied, move to the Tens column : 2 vs. 5.
Triple Digit Treasure Practice Worksheet Digit Dynamics • Lesson 2 Practice
Triple Digit Treasure
Explore standard, expanded, and base-ten representations of three-digit numbers.
Name:
Date:
Value Key: 1 Hundreds Flat = 100 • 1 Tens Rod = 10 • 1 Ones Unit = 1. Use these values to unpack each treasure chest!
Round 1 Base-Ten Treasure Chests: Count and Record
Look at this block arrangement. How much gold is inside?
100
100
10
10
10
Standard Form:
Expanded Form:
Word Form:
Look closely! Are there any tens rods in this box?
100
100
100
No Tens
Standard Form:
Expanded Form:
Word Form:
Round 2 Accordion Stretch: Write in Expanded Form
582
=
419
=
607
=
850
=
Digit Dynamics Curriculum • Triple Digit Treasure Page 1 of 2
Digit Dynamics • Lesson 2 Practice
The Crocodile's Rule: Start comparing in the Hundreds Place . If they are equal, compare the Tens Place . If they are still equal, look at the Ones Place !
Round 3 The Crocodile's Choice: Compare using <, >, or =
342
324
506
560
881
881
199
201
713
709
654
655
Round 4 Treasure Chest Riddles: Crack the Code!
RIDDLE 13
I have 4 hundreds, 12 tens, and 3 ones . What three-digit number am I?
Triple Digit Treasure Exit Ticket Digit Dynamics • Quick Check
Triple Digit Treasure Exit Ticket
Show what you know about three-digit place value and comparisons!
Name:
Date:
Solve the three-digit math challenges below. Be sure to look at place values carefully!
Problem 1
Unpack the Number:
Fill in the blanks to represent the number 624 in different ways.
Number: 624
Expanded Form:
How many Hundreds?
How many Tens?
How many Ones?
Problem 2
Crocodile Challenge:
Draw < , > , or = inside each yellow comparison circle.
Think: Look at the hundreds first!
482
485
710
701
350
350
Problem 3
Crack the Regrouping Riddle:
Sienna has 5 hundreds flats, 14 tens rods, and 8 ones blocks . She says her blocks make the number 5148 .
Correct Number:
Digit Dynamics Curriculum • Triple Digit Treasure Exit Ticket • Page 1 of 1
