M2.4.5 Chapter 5
The number line, past 1
I saw 5/4 on a page. Can a fraction be more than 1?
Your guess
Pick one before you read on. It is fine to be wrong.
By the end you can
- Find a fraction on a number line
- Tell if a fraction is before 1, at 1, or past 1
- Count steps past 1 to place a fraction such as 5/4
A number line is a straight line with numbers on it. Each number has its own place.
Fractions are numbers too. They have places on the line, between the whole numbers.
Draw it first
Find 5/4 on a number line
1 Draw a line. Mark 0, 1 and 2 with equal gaps.
2 Cut each whole into 4 equal steps. Each step is 1/4.
3 Count 5 steps from 0. You land on 5/4. It is past 1.
Four steps of 1/4 reach 1. So 4/4 is the same place as 1.
Look at the top and bottom numbers. Is the top bigger than the bottom? Then the fraction is past 1.
See it three ways
With things
Take two strings, each 1 metre long. Cut each one into 4 equal pieces. Lay 5 pieces end to end.
As a picture
In symbols
5/4 = 4/4 + 1/4. That is 1 and one more quarter.
Try it
Walk past 1 with paper strips
You need: two strips of paper of the same length, a pencil.
- Fold one strip in half. Fold it in half again. Open it.
- Do the same with the other strip. Each strip has 4 equal parts.
- Lay the strips end to end. Write 0 at the left end.
- Count 4 parts from 0. Where the first strip ends, write 1.
- Count one more part. Write 5/4 at the end of that part.
What you will see: The fifth part is on the second strip. So 5/4 is past 1.
A wrong idea many people have
A fraction is always less than 1.
Why it feels right: Most fractions we cut are pieces of one whole.
The test that breaks it: Cut two breads of the same size, each into 4 equal pieces. Take 5 pieces. You hold more than one whole bread.
What is true: A fraction can be less than 1. It can equal 1. It can be more than 1. If the top is bigger than the bottom, it is past 1.
Key words
- number line
- a line where every number has its own place.
- steps
- the equal parts of a whole, on a number line.
Back to your guess
The answer is B: Yes. Count more parts than one whole has. You go past 1.
A fraction is a number. It has a place on the number line. Five quarters sits after 1.
Check yourself
Try each one before you look. A wrong answer tells you where to go next.
Count the steps from 0. Which point is at 5/4?
See the answer
Point B
B is 5 steps from 0, and each step is 1/4. So B is 5/4.
- If you chose A: A is 3 steps from 0. That is 3/4, before 1.
- If you chose C: C is 7 steps from 0. That is 7/4, past 1 but too far.
Is 6/4 before 1, at 1, or past 1?
See the answer
Past 1
4 steps of 1/4 reach 1. 6/4 has 6 steps, so it is past 1.
- If you chose A: You may think a fraction is always small. Here the top, 6, is bigger than the bottom, 4.
- If you chose B: Only 4/4 is at 1. 6/4 is two more steps along.
Each whole is cut into 3 equal steps. Point P is the first tick after 1. What fraction is P?
See the answer
4/3
1 is 3 steps from 0. One more step makes 4 steps. Each step is 1/3, so P is 4/3.
From an earlier chapter
Amina eats 3 of the 4 equal parts of a bread. What fraction of the bread did she eat?
Draw a number line from 0 to 2. Cut each whole in half. Mark 3/2.
See the answer
Mark 0, 1 and 2. Mark the middle of each whole. Count 3 half steps from 0. You land on 3/2, halfway between 1 and 2.
Each step is 1/2. Two steps reach 1, and one more step makes 3/2.
What fraction is point Q?
See the answer
5/2
Each step is 1/2. Q is 5 steps from 0, so Q is 5/2.
- If you chose A: The bottom number is how many steps make one whole. That is 2. The top number counts the steps from 0.
- If you chose C: You counted the tick at 0 as a step. Count the steps after 0.
Which of these fractions is past 1?
See the answer
9/6
6 steps of 1/6 reach 1. 9/6 has 9 steps, so it is past 1.
- If you chose A: 5 steps of 1/8 do not reach 1. You need 8 steps.
- If you chose B: 6 steps of 1/6 reach 1 exactly. It is at 1, not past it.
Kofi counts steps of 1/3 from 0 and lands on 5/3. How many steps does he count?
See the answer
5 steps
The top number counts the steps from 0. 5/3 is 5 steps of 1/3.
- If you chose B: There are 3 steps in each whole. Kofi went past 1, so he counted more than 3.
- If you chose C: There are 2 steps past 1. Kofi counted every step from 0.
Priya says 7/4 is past 1. She says the top is bigger than the bottom. Is she right?
See the answer
Yes. The top is bigger than the bottom.
4 steps of 1/4 reach 1. 7/4 has 7 steps, so it is past 1.
- If you chose A: A fraction can be more than 1. 7 steps of 1/4 go past the 4 steps that reach 1.
- If you chose C: Only 4 quarters make one whole, 4/4. 7/4 is 3 more steps along, so it is past 1.
Keep it
Copy this into your exercise book.
A fraction is a number with a place on the number line. Cut each whole into equal steps. Count the steps from 0. Top bigger than bottom? You are past 1.
Draw: A line from 0 to 2. Cut each whole into 4 steps. Mark 5/4, just past 1.