Column Crunchers Slides GRADE 2 MATH
Column Crunchers
Subtracting with Place Value Power
10
TENS
1
ONES
Warm-up: Fast Tens
How many ones?
3 Bundles = ___
1 Bundle = 10 Sticks
When I show a card, shout out how many ones you see as fast as you can!
6 Bundles?
8 Bundles?
Watch & Learn
0:00 - 2:35
Embedded media
PLACE VALUE POWER!
Pause at 0:25
Why are the numbers different colors?
Pause at 1:20
Predict the answer before he finishes!
"Start in the ones place... everything in yellow is the ones column."
Activity: Color-Coded Columns
1
Grab your purple and yellow pencils.
2
Look at the ones column first. Subtract the yellow numbers.
3
Look at the tens column. Subtract the purple numbers.
6
5
-2
3
?
?
Alignment is Key!
Closure Time!
Show off your place value skills on the Exit Ticket.
Solve the problem
Label the Columns
TENS + ONES = MATH SUPERSTARS!
Column Crunchers Worksheet Column Crunchers
Subtraction Challenge
Name:
Date:
How to Crunch:
Use your purple pencil for the TENS and yellow for the ONES.
Always start with the ones column first!
Subtract the numbers and write your answer in the grid.
1 Let's do this one together!
Tens Ones
6 -2
5 3
2
Tens Ones
8 -4
7 2
3
Tens Ones
5 -1
9 6
4
Tens Ones
4 -3
8 4
5
Tens Ones
9 -5
6 1
Super Cruncher!
Can you make your own column problem? Make sure you don't need to regroup!
Grade 2 Subtraction Made for math superstars
Column Crunchers Exit Ticket Final Crunch
Exit Ticket
Name:
1 Solve the problem using your color strategy!
7
6
-3
4
2 Draw a line to label the columns!
Tens
Ones
Got it!
Almost
Help!
Column Crunchers Teacher Guide Teacher Guide
Lesson: Column Crunchers (2nd Grade Math)
Objective
Subtract 2-digit numbers without regrouping using the standard algorithm.
Materials
Slide Deck, Worksheet, Exit Ticket, Purple & Yellow pencils.
Time
40-45 Minutes total.
1
Warm-up: Fast Tens (5 min)
Show flashcards (or use Slide 2) with bundles of ten sticks. Students should shout out the number represented (e.g., 6 bundles = 60 ones).
Focus: Place Value fluency
2
Interactive Video (10 min)
"Subtracting two digit numbers without regrouping" (Khan Academy)
PAUSE AT 0:07
Ask: "Where should we start subtracting? Left or right?"
PAUSE AT 0:25
Discuss why the numbers are different colors (tens vs ones).
PAUSE AT 1:20
Prediction: "How else can we write 65 using words?" (6 tens + 5 ones).
KEY QUOTE
"Everything in the second column is in the tens place."
3
Main Activity (20 min)
Worksheet: Column Crunchers
Provide students with purple and yellow pencils.
Guide Problem #1 together, explicitly tracing the dotted vertical line.
Circulate and check for alignment . Ensure students are subtracting the ones column first.
Differentiation: For advanced students, encourage the "Bonus Challenge" where they create their own problems (remind them the top digit must be larger).
4
Closure & Exit (5 min)
Students complete the Exit Ticket independently. They must solve 76 - 34 and draw lines to label the 'Tens' and 'Ones' boxes to the correct columns.
LOOK FOR: 42 (Answer) + Correct Place Value Labels
Watch Out For:
Directionality: Students starting from the left. Correct this immediately as it will cause issues later with regrouping.
Digit Value: Students thinking the '6' in 65 is just 6. Reinforce "6 tens".
Column Crunchers Answer Key Answer Key
Column Crunchers Worksheet & Exit Ticket
Worksheet: Column Crunchers
Problem 1
65 -23
42
Problem 2
87 -42
45
Problem 3
59 -16
43
Problem 4
48 -34
14
Problem 5
96 -51
45
Bonus Challenge answers will vary.
Ensure top digits are larger than bottom digits.
Exit Ticket: Final Crunch
76 -34
42
Solution: 42
Left Column: Labeled "Tens"
Right Column: Labeled "Ones"
