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42 votes
42 votes
Order numbers from least to greatest 2.8, -2 3/4, 3 1/8, -2.2

User Rajamohan Sugumaran
by
3.1k points

2 Answers

19 votes
19 votes

Answer:

-2 3/4, -2 2/5, 2.8, 3 1/8

Explanation:

Strategy 1:

What you want to do in this question is convert everything into one unit. So either decimals, or fractions. I find it easier to do this with decimals so here is my steps to solving this.

Since -2 3/4, and 3 1/8 are already fractions we don't need to convert them.

Let's do 2.8 first.

0.8 as a fraction is 8/10, or 80/100 because one way to thing about it is 0.8 is just 0.8/1.0 and if you multiply top and bottom by ten, then you can get 0.8 = 8/10. lets simplify a bit more. 8/10 if you divide by 2 on top and bottom you get 4/5. So 2.8 = 2 4/5

We can do the same thing with -2.2.

All we have to do is do 0.2/1.0 times 10 on top and bottom and we get 2/10. Now we simplify. We can divide top and bottom by 2 without a remainder so if we do that we get 1/5 in simplified form. So -2.2 = -2 1/5

now 4/5, 1/5, 3/4 and 1/8 don't have the same base, so by using LCM (Least Common Multiple) we can figure out that the least common multiple between all of them is 40. All we have to do now is multiply top and bottom in a way that gets us 40 on both bases. (For 4/5 and 2/5 you have to multiply top and bottom by 8 to get 40 and for 3/4 you have to multiply top and bottom by 10 and for 1/8 you have to multiply the top and bottom to get 40.) Once we multiply it all out we get:

2 32/40, -2 30/40, 3 5/40, -2 8/40.

Now if you compare the negatives and the positives greatest to least you get:

Negatives: -2 8/40, -2 30/40

Positives: 2 32/40, 3 5/40

And if you put them together

-2 8/40, -2 30/40, 2 32/40, 3 5/40

Strategy 2:

If you're confident just estimate lol (When your'e at a higher level.)

Disclaimer: Doesn't work for all problems just the easy ones

User Kevin Nisbet
by
3.0k points
19 votes
19 votes

Answer:

-2.2, -2, 1/8, 3/4, 2.8, 3

Explanation:

User DextrousDave
by
3.2k points