Lesson 10
All Sorts of Denominators
Students add and subtract fractions where neither denominator divides the other. Two strategies: product of denominators, or finding a smaller common multiple.
Student Reasoning Map · Fraction Addition
L0
No partitioning
Marcus J.
L1
Halves only
Destiny W.
Amira K.
L2
"Add everything"
Sofia M.
Ethan C.
Fatima A.
Noah B.
Lily T.
Omar H.
L3
Procedure only
Isabella G.
Liam P.
Aisha N.
Tyler K.
Zara M.
Jaylen
L4
Equivalence
Emma R.
Carlos D.
Maya S.
L5
Flexible
Jackson W.
Chloe L.
Leo F.
L6
Fluent
Olivia H.
Nia J.
Ryan T.
Sophia C.
Ben K.
Warm-Up
How Many Do You See?
Sofia's group will count squares but won't connect to fraction ops
10 to watch
▾
Core
Finding Common Denominators
Highest risk. "Add everything" group will apply their broken algorithm
6 at risk
▾
Core
Denominator Strategies
Well-matched for most. Pair solid students with procedure-only students
Most ready
▾
Synthesis
How Did You Decide?
Listen for "that's the rule" answers. If you hear them, the gap persists
Check understanding
▾
Prep Checklist for Lesson 10
1
Bring fraction strips (halves, thirds, fourths, fifths, sixths). Place a set at Marcus, Destiny, Jaylen, and Amira's tables.
2
Seat Sofia, Ethan, Fatima, Noah, Lily, Omar near each other so you can circulate quickly during Activity 1.
3
Plan pairs for Activity 2: Jackson + Isabella, Emma + Liam, Carlos + Aisha, Maya + Jaylen.
4
Print the warm-up area diagram for the "add everything" group to reference during Activity 1.
After Lesson 10 · Quick Check
Answer these after class. MCT will use your responses to adjust Thursday's Lesson 11 prep.
Did the "add everything" group use a common denominator in the Cool-Down?
If no → MCT will flag a 10-minute small-group pull at the start of Lesson 11
Could any procedure-only student explain WHY common denominators work (not just how)?
If no → MCT will add a "same-size pieces" visual to Thursday's warm-up, targeting Isabella, Jaylen, and Liam
Did Marcus or Destiny engage with the fraction strips during the warm-up?
If no → MCT will recommend fraction strips all week + peer mentor for Lesson 11
The loop: Diagnose (MCT interviews) → Adapt (today's lesson) → Verify (this check) → Plan (tomorrow's Lesson 11). MCT updates Thursday's prep automatically.