"Could I have a 3.65 and an 0.8, please ... ?" Show
Ordering decimals can be tricky. Because often we look at 0.42 and 0.402 and say that 0.402 must be bigger because there are more digits. But no! We can use this method to see which decimals are bigger:
Example: Put the following decimals in ascending order:1.506, 1.56, 0.8 In a table they look like this:
Fill in the empty squares with zeros:
Compare using the first column (Ones)Two of them are "1"s and the other is a "0". Ascending order needs smallest first, and so "0" is the winner: Answer so far: 0.8 Now we can remove 0.8 from the list:
Compare the TenthsNow there are two numbers with the same "Tenths" value of 5, so move along to the "Hundredths" for the tie-breaker Compare the HundredthsOne of those has a 6 in the hundredths, and the other has a 0, so the 0 wins (remember we are looking for the smallest each time). In other words 1.506 is less than 1.56: Answer so far: 0.8, 1.506 Remove 1.506 from the list:
Only one number left, it must be the largest: Answer: 0.8, 1.506, 1.56 Done! Example: Put the following decimals in DESCENDING order:0.402, 0.42, 0.375, 1.2, 0.85 In a table they look like this:
And we want to go from highest to lowest (descending). Fill in the empty squares with zeros:
Compare using the first column (Ones):There is a 1, all the rest are 0. Descending order needs largest first, so 1.2 must be the highest. (Write it down in your answer and cross it off the table). Answer so far: 1.2
Compare the Tenths.The 8 is highest, so 0.85 is next in value. Answer so far: 1.2, 0.85
Now there are two numbers with the same "Tenths" value of 4, so move along to the "Hundredths" for the tie-breaker One number has a 2 in the hundredths, and the other has a 0, so the 2 wins. So 0.42 is bigger than 0.402: Answer so far: 1.2, 0.85, 0.42, 0.402
Only 0.375 left, so the answer is: Answer: 1.2, 0.85, 0.42, 0.402, 0.375
Now, go practice with this special Decimal Ordering Game ! Copyright © 2017 MathsIsFun.com |