ISRM is the world's largest free digital repository of all things concerning slide rules and other math artifacts.
As of 2023, ISRM is celebrating its 20th Anniversary!
ISRM is an IRS 501(c)(3) (A57 - Science and Technology Museums) non-profit corporation through the State of Colorado.
Colorado ID Number 20181884948, IRS EIN 83-2486423. - ISRM Advisory Board of Directors.
KEEP ISRM FREE! Donations are tax deductable
2022 was the 400th anniversary of the slide rule as described by Willaim Oughtred.
2022 was also the 50th anniversary of the HP-35 Electronic Slide Rule Calculator.
Visit What's New! for the latest additions to the galleries and changes to the website.
ISRM is best viewed on a desktop. Clear your browser cache often CTRL+F5 or Press Post and Chat on
ISRM @sliderulemuseum and
Instagram page
On-line virtual face-to-face coffee.social get together. Three times/week.
Two times on Wednesday and once on Saturday. The UTC time will change according to Colorado Daylight Savings Time.
2nd shift: WED. at 9 PM Mountain Daylight Savings Time (3 AM UTC THU.)
1st shift: WED. at 9 AM Mountain Daylight Savings Time (3 PM UTC WED.)
Weekend 3rd shift: SAT. at 9 AM Daylight SavingsTime (3 PM UTC SAT.)
The meeting are put into three sessions because of Google Meet's one-hour limitations on a free account (Google will give use a 5-minute-warning as the end approaches):
2023 Special Fund Raiser for capital Equipment - Completed, Thank you!
22 donors 100% of goal as of Aug 24, 2023
2023 Annual Fund Raiser
11 donors 91% of goal as of Oct 24, 2023
ISRM needs to raise a minimum of $2000 annually, necessary for its programs, exhibits,and ongoing web maintenance. All donations are tax deductable. In our 19th year of being on-line, we have data being downloaded from 118 countries, all at no cost to you! There are no paid staff members, but we need help in keeping ISRM growing and on-line during these challenging times. In 2011 ISRM established a FRIENDS OF THE MUSEUM page to acknowledge its many supporters. You can become a TIER 1 FRIEND OF THE MUSEUM by your donation through Paypal or by check. You can also help by participating in ISRM's Slide Rule Rescue program where you can adopt slide rules. Note that ISRM is a 501(c)(3) non-profit so cash donations are tax deductable. Thank you for your welcome support and kind consideration!
Mail checks or donated items to: ISRM, 1944 Quail Circle, Louisville, CO 80027, USA.
Students from the Collège André-Grasset in Montreal, Canada using slide rules donated by ISRM. Click on the banner for more information.
Dr. Barbara Rooker of the Joplin, Missouri K12 School System, introduced students to slide rule math during 2009 using ISRM's free loaner program. Click banner for more pictures:
ISRM @sliderulemuseum
Instagram page
