Decimals
OOPS! Just realized I forgot to post this before vacation!
We have started to study decimals in math. As we begin, we look at money as one way to understand them. Five dollars and two cents is written $5.02 (NOT 5.20!). From here, we review place value and extend it to the right of the decimal. We have a chart up in class.
At this stage, we are representing fractions as decimals, decimals as fractions, and ordering fractions and decimals from least to greatest. Here are a few common mistakes kids make.
- A fraction such as 7/100 is represented as 0.07 (the 7 is in the hundredths place) as opposed to 0.7 (which is 7/10 with the 7 in the tenths place).
- A fraction such as 23/50 must be converted to hundredths before converting it to a decimal. 23/50 = 46/100 = 0.46
- When ordering decimals from least to greatest, you must pay attention to place value. 0.6 is greater than 0.59 – (The number in the tenths place is what is most important here!) 16.01 is greater than 16.0045 -
I recommend that kids do a couple of things.
- Recognize the equivalent decimals of common fractions such as:
- 1/4 = 0.25, 1/2 = 0.5, 3/4 = 0.75
- 1/5 = 0.2, 2/5 = 0.4, etc.
- 1/3 = 0.333. . . which rounds to 0.33, 2/3 = 0.6666. . . which rounds to 0.67.
- 1/8 = 0.125, 3/8 = 0.375, etc. (These are handy to know, but less important than the previous
- Practice! Web sites at our portaportal are a good place to find practice exercises.
