Sanban is a grid chart with each column expressing numbers such as one, ten, one hundred, one thousand, ten thousand, and each row expressing answers to algebraic equations and their coefficients, such as "sho" (answer), "jitsu" (constant term), "ho" (x), "ren" (x2), "gu" (x3), "sanjo" (x4) and so on.
算盤とは碁盤の目状になった表であり、各列が一、十、百、千、万といった桁を表し、各行は商（答え）、実（定数項）、方　(x)、廉(x2)、隅(x3)、三乗(x4)…と代数方程式の解および各係数を表した。