The Square Decimeter
A square decimeter is slightly bigger than a piece of sliced cheese.

A square decimeter,
(dm²), is used to measure area in the metric system.

In math, area means the amount of space inside a  two-dimensional shape.

A
dm² is one of six sides of a cubic decimeter  which is  used for measuring the volume of liquids and gases. This makes it an important  measuring tool used in the metric system of measurements.

Area is  measured in square units, like a square meter.

(dm²)
The Teacher's Corner
How to choose the proper material, and cut 50 hardboard square decimeter templates.
1m
1m
                Hardboard
Hardboard, which comes in two basic thicknesses, 1/8” and ¼”  (3mm & 6mm)  is an ideal material to make durable templates.

You can use a “Dry Erase Marker” on white hardboard. You can use blackboard paint to make specialized blackboards with tempered brown hardboard.
Brown tempered hardboard
Brown tempered hardboard painted with blackboard paint.
White tempered hardboard.
If your students make a mistake and use a permanent marker on white hardboard you can use blackboard paint to cover the markers. Now you have a 1dm square mini blackboard.

The two photos below are photos of each side of a small  hardboard panel (2' X 4').  I purchased the panel from a building supply store. One surface is brown the other is white. 

Before you choose a store, go to their website and search for hardboards. Make a note where to find them in the store.
 
Chalkboard Circle Protractor
Chalkboard Templates
Inquire if they custom cut material.  Custom cutting means you can have material precisely cut to the size you want. You may need that service in the future. Always check what the cost will be.

The 1dm/square  hardboard that we are going to create is a great material for ten-year-old kids to use as a template. A template is a measuring tool.

Hardboard is not an appropriate material for ten-year-old kids to use as a building material because it is difficult to cut with basic hand and power tools. That being said, let’s discuss three methods you can create  50 square decimeters.

This is important before you start! First and foremost establish a reasonable budget with your Principal, ($10.00/student). With these funds you will be able to buy one sheet of the 2ft by 4ft hardboard and other tools and materials.

You have three choices on how to cut the hardboard sheet to size.

Cutting to size means ripping it to 10cm wide and cutting the 5 strips created to a length of 10cm. You will end up with about 50 square decimeter templates.

Hardboard is difficult to cut. You need sharp, precise tools and know-how.

Choice #1: Cut it yourself. Do you have the proper tools? Do you have the know-how? Warning, if you don't, don't mess around with this material. It’s not called hardboard for nothin’.

Choice #2: If you don’t feel confident in cutting the dm squares to size, when you are writing a letter to your parent’s requesting  them to organize the boxboard (cereal boxes), ask if anyone has the tools and skills to cut your board to size.

Finding a volunteer parent with skills would be a real find for you as a teacher. Not only will you save money but you will have someone to discuss your future tech designs.

Choice #3: Negotiate cutting the material to size with you building supply store.

Convert your simple square decimeter to a more complex measuring and design tool.
One square meter equals one hundred square decimeters.The ratio between square decimeters and square meters (the standard) is 100:1,meaning there are 100 square decimeters in 1 square meter.