First we have to understand how to read numbers. Then we need to comprehend that a series of numbers can be read not only horizontally (e.g. in a poster) but also vertically. Then we must make the connection that a small line represents one number. Most thermometers do not have every number marked, they only have lines. My thermometer has numbers marked by 10s (e.g. 0, 10, 20, 30 etc.). Making the leap from reading a numbered line to an unnumbered line can be quite a challenge. Here is what I recently did to help my students read our outdoor thermometer.
1. Get the numbers down. Read them in order, do cloze exercises with the number sequences, etc.
2. Demonstrate on the board that numbers can be read vertically (upwards) and practice reading this together. Have students present it.
3. Put notches / lines beside each number and read it again.
4. Erase some numbers and have students write the missing numbers.
5. Discuss what a thermometer is. I did this by bringing my thermometer into the kitchen and putting it in the freezer to see the colour move down, and then run it under hot water to see it rise. This demonstrates the concept well.
6. On the board draw a thermometer and explain how the "colour stops" at a number and that is the temperature. Do a few examples and have students read the numbers.
7. I printed off worksheets from here: http://worksheetgenius.com/html/thermometers.php
8. Return to the board and erase the middle numbers and mark it only by 5s or by 10s and draw the temperatures again.
Ideally this would be started in the fall or the spring when the temperatures are not yet in the minus numbers.
You could also create your own paper thermometers for a hands-on practice of reading thermometers. I would suggest write lines for each number.
Outomes: Read numbers, Read temperatures, write numbers, listen and show temperature, follow instructions
