Step by step
The question
Question: put −0.25, −1/5, 0.1, −3/10 in order, from smallest to largest.
1 Write each as a decimal
To compare, we write every number the same way: as a decimal.
A decimal is tenths, hundredths or thousandths.
5 times 2 is 10.
So we multiply the top and the bottom by 2.
2 tenths is 0.2.
The minus sign stays in front: −0.2.
3 tenths is 0.3.
The minus sign stays in front: −0.3.
2 Same number of digits
Zeros at the end of a decimal do not change it: −0.2 is the same as −0.20.
So we give every number 2 digits after the point.
3 Compare
Negative numbers are below 0.
30 > 25 > 20, so the first one is further below 0.
Further below 0 means smaller.
Careful!
0.3 is more than 0.25.
But −0.3 is further below 0, so it is smaller.
Negative numbers are smaller than every positive number.
So they come first.
4 Write the answer
Now we write the numbers as they were given, in the same order: −3/10, −0.25, −1/5, 0.1.
5 Check
Let's check on a number line.
Smaller numbers are further to the left.
We put a dot for each number.
From left to right: −3/10, −0.25, −1/5, 0.1.
The same order.
So the answer is right!
Let's look back.
First: write each as a decimal.
Then: same number of digits.
Then: compare.
Then: write the answer.
Last: check.