Average
#278 of 381 private schools in WA
Cornerstone Montessori School
Elementary School · Sumner, WA
A private elementary school in Sumner, WA serving grades Pre-K – 6th.
1644 GAULT ST, Sumner, WA 98390
- 7.6:1 student-teacher ratio
Academics
PreliminaryWhat this rating measures
This rating reflects classroom size, instructional time, student diversity, community resources, and school characteristics. Private schools are ranked against other private schools in WA.
Data not available
View data sources
Score basis: Private school model
Data coverage: 80% of scoring components had data
Components scored: 4 of 5
Ranking pool: Private schools in WA
Test scores
Most recent published year. School vs. WA average.
Test score data not yet available for this school.
How we rate schools
A clear 1–10 score built from public data — growth, academics, and learning environment. No hidden criteria, no pay-to-play.
See how we rateThe neighborhood
Where Cornerstone Montessori School sits, and what the surrounding area looks like.
Nearby same-level schools are colored by their score. Pins are locations, not attendance boundaries. Open the Seattle map →
Getting around & local context
- Walk 34Car-Dependent
- Bike 51Bikeable
- City Safety: High3,671/100K
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FBI Uniform Crime Reporting · 2024 · city context (Sumner), not school-level safety or attendance eligibility. Source details
Source period: 2024. Freshness not available.
Area profileU.S. Census ACS 5-year estimates (ACS 2019–2023 5-year estimates)
Median income
$97,815
Median home value
$471,500
Median rent
$1,886/mo
College educated
23%
Homeownership
51.3%
Poverty rate
6.9%
ACS 2019–2023 5-year estimates for the ZCTA associated with school ZIP 98390; this is area context, not an attendance boundary.
Programs & students
Student demographicsNCES Private School Universe Survey (PSS) (SY 2021–22)
Source: NCES Private School Universe Survey (PSS)
Compare nearby
Nearby same-level schools
4 from a 5-mile search
| School | Score | Grades | Distance | Enrollment | Compare |
|---|---|---|---|---|---|
| Maple Lawn ElementaryEnrollment path unverified | 8.6 | PK–5 | 0.1 mi | 603 | Compare → |
| Sumner Special ServicesEnrollment path unverified | Not rated | PK | 0.9 mi | 52 | Compare → |
| Daffodil Valley ElementaryEnrollment path unverified | 6.8 | PK–5 | 1.1 mi | 521 | Compare → |
| Northwest Christian SchoolPrivate · tuition | 6.3private | PK–8 | 1.4 mi | 154 | Compare → |
Distance is proximity only; it is not attendance eligibility.
Enrollment path unverified: Potential public school; its attendance or application path has not been classified.
Private · tuition: Potential private option; tuition and admission requirements have not been verified.
Public and private scores come from different models and are shown side by side, not blended into one ranking.
Cornerstone Montessori School is listed in Sumner, WA; verify the current enrollment path directly.
About Cornerstone Montessori School
Cornerstone Montessori School is a private elementary school in Sumner, WA, serving approximately 38 students in grades Pre-K-6th with a 7.6:1 student-teacher ratio. It holds a MySchoolScout rating of 5.7 out of 10 and ranks #278 of 381 private schools in WA.
Frequently asked questions
Common questions about Cornerstone Montessori School
What grades does Cornerstone Montessori School serve?
Cornerstone Montessori School serves students in grades Pre-K through 6th.
How many students attend Cornerstone Montessori School?
Cornerstone Montessori School has an enrollment of approximately 38 students.
What is the student-teacher ratio at Cornerstone Montessori School?
The student-teacher ratio at Cornerstone Montessori School is 7.6:1. A lower ratio generally means more individual attention per student. The national average is approximately 11:1 for private schools.
How does Cornerstone Montessori School rank in WA?
Cornerstone Montessori School ranks #278 of 381 private schools in WA.
What is Cornerstone Montessori School's MySchoolScout rating?
Cornerstone Montessori School has a current MySchoolScout rating of 5.7 out of 10. This score combines the level-appropriate components shown in the rating breakdown; equity data is shown separately for context.
Is Cornerstone Montessori School a private school?
Yes, Cornerstone Montessori School is a private coeducational school with a Nonsectarian affiliation. Private schools are not required to participate in state standardized testing, so academic performance data may be limited compared to public schools.
Is Cornerstone Montessori School a religious school?
No, Cornerstone Montessori School is a nonsectarian (non-religious) private school.
School factsNCES Private School Universe Survey (PSS) (SY 2021–22)
- Grades
- Pre-K – 6th
- Enrollment
- 38
- Gender Split
- 55% M / 45% F
- Student-Teacher Ratio
- 7.6:1
- Teachers (FTE)
- 5
- Type
- private
- Coed Status
- coed
- Affiliation
- Nonsectarian
- School Day
- 6 hours
- Days Per Year
- 190 days
- Setting
- Large Suburb
- County
- Pierce County
- Phone
- (253) 987-7239
- Area population (ZIP 98390)
- 11,497
- Area average commute
- 30.2 min
- Area median age
- 35.9
About this school's data
Every number on this page comes from a published source with a stated period. Where a source is partial, aging, or describes a surrounding area rather than the school, that limitation is named below.
- School directory (enrollment, grades, staff, contact)
- NCES Private School Universe Survey (PSS) · SY 2021–22 · Low confidence
- Vintage not available. Do not use this measure alone.
- MySchoolScout rating and rank
- MySchoolScout ranking model · Low confidence
- Vintage not available. Do not use this measure alone.
- Available for part of the eligible units; results may not represent the full area.
- Derived as a weighted blend of the component scores shown in Academics from state assessment, EdFacts growth, and NCES resource records.
- Neighborhood (income, housing, education)
- U.S. Census ACS 5-year estimates · ACS 2019–2023 5-year estimates · Low confidence
- Older source: ACS 2019–2023 5-year estimates. Use as historical context.
- Reported for the ZCTA for ZIP 98390; this does not measure the attendance area.
Evidence periods: Rating mixed/unknown input periods; assessments vintage unavailable; directory SY 2021–22
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