Adding Decimals

Students looked at how to add decimals today.  First, we took a horizontal equation and attempted to correctly write it vertically then add it.  Next, we took the different answers and placed them on the board.  Then, students voted on the correct answer and volunteers came up to state their reasoning as to why they chose that answer.  Through our dialogue, opinions changed and through proofs students all came to a consensus as to how to write the equation and why, thus deriving at the correct answer.

Fractions as Decimals

Today students learned how to make fractions into decimals when the denominator is not 10 or 100.

Students discovered that in order to do this you need to make an equivalent fraction with a denominator or 10 or 100.  So students had to analyze the fraction and decide whether the current denominator was a factor / multiple of 10 or 100, and then work to convert that fraction into an equivalent one and follow up with then making it into a decimal.

I was pleased at how well the students applied their previous knowledge to this task and took to being able to grasp this concept quickly.

Comparing Decimals

Students are getting to the point in their math decimals unit where they are comparing fractions.  Therefore, they are looking at 0.1 more/less and 0.01 more/less, along with then increasing this amount to find numbers that fit their clues.  Today we introduced this concept using place value mats, with places consisting of tens, one, tenths, hundredths, and place value chips.  First we practiced building given numbers using these tools, and then we extended this knowledge of find more and less than numbers with clues.  Using manipulatives helps us build our understanding of the concept, and to see it visually before we enter the abstract math world.  Comparing numbers will also have us ordering and using our >, <, and = signs again.

Comparing Decimals

Students had an introductory lesson on how to compare decimals today.  We started by comparing tenths to tenths, then hundredths to hundredths.  We found that comparing decimals is just like comparing whole numbers: pay attention to the place value of each digit.  Students extended their comparison to comparing decimals with similar tenths but different hundredths, and hundredths to numbers with only tenths.  We realized that it's not hard; we just have to remember that 0.9 is equivalent to 0.90 and this knowledge helps us in our comparisons.

Decimals

This week the students have been learning about decimals.  We've started out with tenths (the first place value after the decimal point).  The students have learned that we use a base 10 system so our magic number is 10 (that's how many fractional parts are in a tenth), how to convert a fraction to a decimal and vice versa (both improper, mixed and regular fractions), how to read and write in words a decimal, and how to accurately place it on a number line.