Ten's Complement

Definition

Hi friends! Today, let's have fun with the number 10. Do you know our friend, number 10?Imagine we have a special treasure box that can hold exactly 10 gold coins. Right now, there are 7 gold coins in the box.

How many more gold coins do we need to fill the treasure box?

Answer

We need 3 more gold coins to make 10.

This is called finding the complement to 10.

Definition 10's Complement

The 10's complement is the number we add to make 10.

Number	Complement	Sum	Cubes	Circles	Fingers
\(\textcolor{colordef}{1}\)	\(\textcolor{colorprop}{9}\)	\(\textcolor{colordef}{1}+\textcolor{colorprop}{9}=10\)			\(+\)\(=\)
\(\textcolor{colordef}{2}\)	\(\textcolor{colorprop}{8}\)	\(\textcolor{colordef}{2}+\textcolor{colorprop}{8}=10\)			\(+\)\(=\)
\(\textcolor{colordef}{3}\)	\(\textcolor{colorprop}{7}\)	\(\textcolor{colordef}{3}+\textcolor{colorprop}{7}=10\)			\(+\)\(=\)
\(\textcolor{colordef}{4}\)	\(\textcolor{colorprop}{6}\)	\(\textcolor{colordef}{4}+\textcolor{colorprop}{6}=10\)			\(+\)\(=\)
\(\textcolor{colordef}{5}\)	\(\textcolor{colorprop}{5}\)	\(\textcolor{colordef}{5}+\textcolor{colorprop}{5}=10\)			\(+\)\(=\)
\(\textcolor{colordef}{6}\)	\(\textcolor{colorprop}{4}\)	\(\textcolor{colordef}{6}+\textcolor{colorprop}{4}=10\)			\(+\)\(=\)
\(\textcolor{colordef}{7}\)	\(\textcolor{colorprop}{3}\)	\(\textcolor{colordef}{7}+\textcolor{colorprop}{3}=10\)			\(+\)\(=\)
\(\textcolor{colordef}{8}\)	\(\textcolor{colorprop}{2}\)	\(\textcolor{colordef}{8}+\textcolor{colorprop}{2}=10\)			\(+\)\(=\)
\(\textcolor{colordef}{9}\)	\(\textcolor{colorprop}{1}\)	\(\textcolor{colordef}{9}+\textcolor{colorprop}{1}=10\)			\(+\)\(=\)