109-110 Large and small abacus
111-115 Slide rules
116 Chemical calculator
117 30 foot slide rule
118 Load adjuster
119-121 More slide rules
122 Tasco arithometer
123 Brunsviga adding machine
124 Early calculator
126 Star finder
127 Astrogation compass
128 Small compass
129 Drafting tool
130 Planimeter
131 Mathematical typewriter
135 Munro calculator