Teacher Investigation Guide
Digit Detectives
15-Day Number Mastery Guide
"Cracking the code of numbers 0-100 through writing, sequencing, and place value investigation."
Phase 1
Days 1-5: The Base Camp. Mastering 0-20 with a focus on teen numbers.
Phase 2
Days 6-10: The Great Climb. Exploring 20-50 and the power of tens.
Phase 3
Days 11-15: The Summit. Reaching 100 with place value precision.
Master Investigation Plan
15-Day Curriculum Calendar
Week 1: Numbers 0-20
Day 1
The Pretest Case
Administer Pretest. Initial count-aloud to 20.
Day 2
Tracing Clues
Number formation (0-10). Writing practice.
Day 3
Teen Town
Understanding 11-19 as "10 and some more."
Day 4
Missing Links
Sequencing 0-20. What comes before/after?
Day 5
Checkpoint Alpha
Formative Check: Writing & Sequencing 0-20.
Week 2: Numbers 20-50
Day 6
The Tens Group
Counting by 10s to 50. Grouping objects.
Day 7
Building 50
Base-ten blocks. Writing numbers in 20s/30s/40s.
Day 8
Number Race
GAME DAY: Number Race (0-50 board).
Day 9
Pattern Patrol
Finding patterns on the hundreds chart (to 50).
Day 10
Checkpoint Beta
Formative Check: Value & Sequencing 20-50.
Week 3: Numbers 50-100
Day 11
The Hundred Hike
Counting 50-100. Identifying numbers in isolation.
Day 12
Value Vault
Comparing values: Greater than/Less than to 100.
Day 13
Showdown
GAME DAY: Place Value Showdown (0-100).
Day 14
Final Review
Whole chart review. Sequencing wrap-up.
Day 15
The Final Case
Summative Assessment: Mastery 0-100.
Instructional Tip
During Phase 1, pay close attention to number reversals (e.g., 12 vs 21). Use the Detective Log daily to note students who need sensory tracing or more manipulatives. For Phase 2 and 3, emphasize that the first digit tells "how many tens" and the second tells "how many ones."
Mission Objectives
Learning Targets & Success Criteria
Phase 1: Base Camp (0-20)
Learning Target
I can write and sequence numbers 0–20 and explain that teen numbers are "ten and some more."
Success Criteria
- I can write digits 0–9 without reversals.
- I can fill in missing numbers on a 0–20 number line.
- I can build teen numbers using a ten frame.
Phase 2: The Great Climb (20-50)
Learning Target
I can read, write, and compare numbers up to 50 using tens and ones, and skip count by 10s from any number.
Success Criteria
- I can skip count by tens starting from numbers like 4, 14, 24...
- I can draw base-ten blocks to represent a number up to 50.
- I can identify which of two numbers is larger by looking at the tens digit.
Phase 3: The Summit (50-100)
Learning Target
I can sequence and master place value for numbers to 100, including skip counting and crossing boundaries.
Success Criteria
- I can skip count by tens starting from any number up to 100.
- I can tell how many tens and ones are in any 2-digit number.
- I can play games to compare values and prove my thinking using place value.
Place Value Showdown Game Cards
Place Value Showdown
Case Game: Comparing 0-100
62
Case Code
85
Case Code
37
Case Code
51
Case Code
19
Case Code
100
Case Code
TEN
TENS
ZERO ONES
How to Play
THE FLIP: Both players flip their top card. The detective with the HIGHER number wins both cards!
CODE RED: If numbers are equal, it's a tie. Flip 3 cards facedown, then 1 faceup. Higher card wins the pile.
THE CODE: Use the bars (tens) and dots (ones) on the card to double-check who has more!
VICTORY: Collect all the clues to win. Practice saying the number aloud as you flip!
Detective Data Log Tracker
Detective Log
Data Collection & Observational Notes
| Investigator Name | Pretest | Form. Alpha | Form. Beta | Summative | Mastery? |
|---|
| Detective A | | | | | |
| Detective B | | | | | |
| Detective C | | | | | |
| Detective D | | | | | |
| Detective E | | | | | |
| Detective F | | | | | |
Reversal Patterns
Note students reversing 12/21, 15/51, or digits like 5 and 2.
Oral Fluency
Note students who struggle with teen naming (eleven, twelve, thirteen).
