Uploaded September 2019 | Updated September 2026, 2 hours ago
The Monroe Calculator is a mechanical calculator that began production from 1914, but only became successful with the introduction of the model K in 1921. Model L followed in 1929, and variants remained in production till the 1960s. In this video I demonstrate the model K, and model L, as well as the electrically driven model KA.
Video of an older model, the model F:
youtube.com/watch?v=fktoCGzqLhI
For more information on the Monroe Calculator, as well as the other mechanical calculators in my collection, visit my website:
jaapsch.net/mechcalc
0:00 Introduction, History
1:05 Model K
1:29 Addition
2:13 Clearing
2:46 Subtraction
3:38 Multiplication
5:13 Counter
6:32 Item Count
9:00 Mechanism
12:46 Model L
13:35 Serial number
13:53 Model designations
15:13 Model L Item Count
15:42 Model KA
16:20 Crank
16:39 Model KA comparison
17:11 Bell
18:35 Model KA add subtract
18:57 Decimal markers
19:55 Outro
The Monroe Calculator is a mechanical calculator that began production from 1914, but only became successful with the introduction of the model K in 1921. Model L followed in 1929, and variants remained in production till the 1960s. In this video I demonstrate the model K, and model L, as well as the electrically driven model KA.
Video of an older model, the model F:
youtube.com/watch?v=fktoCGzqLhI
For more information on the Monroe Calculator, as well as the other mechanical calculators in my collection, visit my website:
jaapsch.net/mechcalc
0:00 Introduction, History
1:05 Model K
1:29 Addition
2:13 Clearing
2:46 Subtraction
3:38 Multiplication
5:13 Counter
6:32 Item Count
9:00 Mechanism
12:46 Model L
13:35 Serial number
13:53 Model designations
15:13 Model L Item Count
15:42 Model KA
16:20 Crank
16:39 Model KA comparison
17:11 Bell
18:35 Model KA add subtract
18:57 Decimal markers
19:55 Outro
