Digit : A digit is a symbol used in the representation of a number.

Number : A number $x$ is a mathematical symbol representing a quantity.

Ten : Ten refers to the number $10.$

Tens digit : The tens digit is the second digit left of the decimal point. For example 31.2 and 32 both have tens digits equal to 3.

Partial products method : A method for calculating a product of two multi-digit numbers by writing both numbers as a sum of ones, tens, hundreds and so on, then multiplying each pair of terms and finally summing up all the terms. For example $12\cdot 34=(10+2)\cdot(30+4)$ $=10\cdot 30+10\cdot 4+2\cdot 30+2\cdot 4$ $=300+40+60+8=408.$

Division : Division is the mathematical operation that divides objects equally into groups. More generally $x\div y$ is defined as the number that if multiplied by $y$ equals $x.$

Standard algorithm : By standard algorithm we refer to any one of the algorithms that are commonly taught at school to add, subtract, multiply or divide multi-digit numbers such as long division and partial products multiplication.