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## Get ready for 3rd grade

### Unit 3: Lesson 2

Fractions of shapes# Halves and fourths

When a whole is divided into equal size pieces, the pieces are fractions of the whole. If the whole is divided into 2 equal sized pieces, each piece is one half of the whole. If the whole is divided into 4 equal sized pieces, each piece is one fourth of the whole.

## Want to join the conversation?

- Are halves two equal parts or it just need to be two parts?(15 votes)
- In maths, it would be two perfectly equal halves, but it really depends on context.

In most case, you would think that halves (and fourths) are equal, like you would think that a half of a pizza is... a half, not some random dusts left over. That random dusts and the part that have been eaten are*two parts*, but they are**not equal**, right?

Moreover, some shapes cannot be divided into two halves. They are**asymmetric shapes**, which do not contain a line of symmetry. A circle, yes, there are halves and quarters. However, a hand, I don't think so.(11 votes)

- do they have to be equal(4 votes)
- Yes all the parts should be equal, and also sum of all the parts should be equal to original diagram.(8 votes)

- Is quarters the same as money quarters?(3 votes)
- Yes they are similar. A quarter is a quarter of a dollar which is $.25(8 votes)

- If a shape is irregular can you still split it in half?(3 votes)
- Every shape, no matter how complicated it is can be split in any number of parts, it just gets harder as shapes get more complicated (a lot harder).(4 votes)

- So the critical part is 'equal'?(3 votes)
- Yes, the parts need to be equal in order to represent fractions properly. For example, if the whole is divided into 4 unequal parts, some parts will be larger than one-fourth and some will be smaller than one-fourth.

Have a blessed, wonderful day!(2 votes)

- Hey! A half is actually quite simple. When you divide a number by 2 you can also say you are putting it into 2 halves. Just remember you can only evenly half even numbers. An even number is any number that ends with 2, 4, 6, 8 or 0.

Example: half of 6 = ?. In this problem, you need to half the number 6 meaning you need to divide 6 by 2. Remember halves have to be 2 equal parts. 6 divided by 2 is 3. the 2 halves of 6 are 3 and 3 and they are equal parts so now you know that is the correct answer. Also, you can see that this is the correct answer because 3 + 3 is 6 so half of 6 is three.

Hope this helps!(3 votes)

- I am not able to achieve a 100% in 1st grade geometry despite having completed the quiz and having watched the video. Does anyone know why?(3 votes)
- To achive 100% in the first grade section, you must achive all of the masterysubjects. If it is too hard, watch a video, but you do not need to watch the videos for the 100%.(2 votes)

- Are fourths as big as a third because, I normally see a third like a fourth(2 votes)
- A fourth is smaller than a third. :)(3 votes)

- When a whole is divided into equal size pieces, the pieces are fractions of the whole.(3 votes)
- What does a dodecahedron look like(2 votes)
- A dodecahedron has 12 flat pentagonal sides.(2 votes)

## Video transcript

- [Voiceover] Which picture
divides a rectangle in half? So to divide something in half we need to divide it into two equal sections. Over here we're divided into two sections but these aren't equal. These don't have the same area. This part has a much
larger area than this one. So this isn't divided in half. This one's also divided into two sections but they're not equal. This one is much bigger than this one. This is divided into equal sections, but it's not two equal sections. This is divided into three equal sections, so this isn't divided in half. Here we're divided into
two equal sections. One, two sections, and they are the same size, the same area. So I'd pick that one. Let's keep going. This is a lot of fun. Which picture divides
a circle into halves? Once again, two equal sections. This one, this one, and this one divide into three sections,
and actually these two right over here, the three
sections aren't even equal. Then here, this is three equal sections but that would be thirds not halves. Halves would be two equal sections, so it'll be that, right over there. Which picture divides
a square into fourths or sometimes people might say divides a square into quarters. Well fourths or quarters
would be four equal sections. Well this is two equal sections. This is one section,
this is just one whole. This is two equal
sections, right over here. Or I guess you could say this one actually is just not divided at all. This right over here
is two equal sections. This is four equal sections,
so this is fourths, or you could say this is
divided into quarters. Let's keep going. Let's do a few more of these. Which picture divides a circle in half? So this circle isn't divided. This is a circle divided into
thirds, three equal sections. This is a circle divided into two pieces, but they're not equal, so this
isn't divided into halves. This is two equal
sections, right over here, so that one is halves. Let's do one more. Which picture divides a
rectangle into halves? Well, it has to be two equal sections. This is three equal sections. This is three not even equal sections. This is three equal sections,
so this would be thirds, just as this one would be thirds. This one over here is two equal sections, so that is halves.