Math Lesson Plan: Introduction to Decimals

Objective: Students will be able to explain what a decimal is.

Lesson Opening

1. We just finished a unit on fractions. By now, you know everything there is to know about fractions. And so we are going to move on to decimals. But actually, you already have a head start on decimals. Decimals are very similar to fractions. So if you understand fractions, you already know a lot about decimals.

1. I'm hungry, so I reach into my pocket to see if I have candy in my pocket. I found 3 whole Starburst and 1 starburst that has a bite taken out of it. There is only half of that Starburst left. Write that as a mixed number.

Guided Practice

1. Decimals were created for exactly the same reason. Any number to the left of the decimal is a whole number: 1,2,3 etc. Any number to the right of the decimal is a fraction, it is smaller than one.

1. Show them what one-tenth looks like on the board using a diagram. Ask them what fraction the picture represents. Now explain that one tenth is written like this: 0.1 Show them how they can write 2 tenths, 3 tenths, 4 tenths etc.

1. Do the same thing with hundredths. Explain that before we can do anything with decimals, you need to know what to call them. If you're going to name a decimal, you say the number after the decimal and then the place that it is in. Remember that the place it is in place value just like tens, hundreds, thousands. You say the decimal as "and."

Independent Practice

1. Have the children complete a quick worksheet where they have to know how to represent a fraction and a decimal pictorially. Tell them that to pay attention because soon they will have to convert a fraction into a decimal and vice-versa.

Closing

1. Ask students if they think decimals will be harder than fractions.