What is Tens and units? — Mathematics

Definition 4.1 Primary & Middle School Mathematics · Chapter 4 — Numbers to 100

A ten is a bundle of ten units. The number $34$ means $3$ tens and $4$ units:

34 = 10 + 10 + 10 + 4 .

The left digit counts the bundles, the right digit the loose units.

Thirty-four sticks: three bundles of ten (each tied with a band) and four loose sticks. No need to count to 34 one by one! — Thirty-four sticks: three bundles of ten (each tied with a band) and four loose sticks. No need to count to $34$ one by one!

The place table of 34: the 3 sits in the tens place, the 4 in the units place. This little table grows a new column every year! — The place table of $34$ : the $3$ sits in the tens place, the $4$ in the units place. This little table grows a new column every year!

Examples

Example 4.2 (Reading the numbers)

$20$ is two tens (twenty), $30$ three tens (thirty) … up to $90$ (ninety) and $100$ (one hundred: ten tens!). In between: $47$ reads “forty-seven” — forty for the $4$ tens, seven for the units.

Example 4.3 (Same digits, different numbers)

$27$ and $72$ use the same digits but are very different: $27$ is $2$ tens and $7$ units; $72$ is $7$ tens and $2$ units — much bigger! The place of a digit decides what it counts.

Read in context →