Compare (Difference Unknown) problems. How many more? How many fewer?
Porównywanie różnicowe. O ile więcej? O ile mniej?
Learning objectives
You will learn to compare natural numbers using their difference and you will use Compare Difference unknown to solve problems.
Learning effect
You compare natural numbers using their difference and solve word problems using this skill.
Introduction:
Think:
- if you have more than 15 friends,
- if you have fewer than 10 favorite TV programmes,
- if you have more than two pets at home,
- if you have read more than 5 books this month,
- if you have fewer than 8 coloring pencils in your pencil case.
Think:
What math skills were needed to correctly follow teacher's instructions? What mathematical relations were used?
Review the following terms: a greater numbergreater number, a smaller number. Solve the task to consolidate these concepts.
Write the appropriate sign in the blank space: <, > or =.
a) 12 ....... 14
b) 59 ........ 57
c) 100 ....... 63
d) 4 ......... 45
e) 124 ....... 42
Open the SLIDESHOW and watch examples of „how many morehow many more?”, „how many fewerhow many fewer?”. Match the appropriate actions to the presented situations.
When you finish present your conclusions.

Zasób interaktywny dostępny pod adresem https://zpe.gov.pl/a/DydrSvgwF
Conclusions:
- If there is a „how many morehow many more” phrase in the problem, we do the additionaddition to solve this problem.
- If there is a „how many fewerhow many fewer” phrase in the problem, we perform the subtractionsubtraction to solve this problem.
Complete the table:
Number x | 8 | 10 | 25 | 30 |
The number 15 greater than x |
Complete the table:
Complete the table. Number x | 62 | 35 | 18 | 100 |
The number 10 less than x |
Complete the sentences.
a) The number 5 greater than 16 is .........
b) The number 32 greater than 48 is ........
c) The number 16 less than 59 is ........
d) The number 14 greater than 68 is .........
The average body heights of selected dog breeds are marked in the picture. The dogs presented are: Bernardine, German Shepherd, Dalmatian, Dachshund, Pug and York.

1. How many centimeters is York shorter than a German Shepherd?
2. How many centimeters is a Dachshund taller than a Pug?
3. How many centimeters is the Dalmatian shorter than the Bernardine?
4. How many centimeters is the German Shepherd taller than a Dachshund?
Solve each of the word problems. Write down all the calculations and the solution.
1. Piotrek's uncle’s car uses 10 liters of petrol per 100 km, and Piotr's father’s car uses 2 less. How many liters of fuel per 100 km does Piotr's dad’s car use?
2. Tomek is 12 years old and his mother is 23 years older than him. How old is Tomek's mom?
3. Zosia has 230 PLN savings. How much less did Krzyś save if he has 150 PLN in his money box?
4. 54 bottles of juice were sold in the school shop on Monday. On Tuesday, the shop sold three bottles fewer than on Monday, and on Wednesday, five greater than on Tuesday. How many bottles of juice were sold during these three days?
Wojtek is two years older than Maciek, and Maciek a year older than Kuba. Wiktor is two years younger than Kuba, and Antek four years younger than Kuba.
The boys are 58 years old together. How old is Kuba? Write down all the calculation and the solution.
Do the revision exercises.
- if in the problem there is a phrase „how many morehow many more”, then to solve the problem we perform the additionaddition;
- if there is a „how many fewerhow many fewer” phrase in the problem, we perform the subtractionsubtraction to solve the problem.
Exercises
The mother is 32 years old and the father is 34. Małgosia is 10 years old, and her brother Jasio 8. Determine which sentences are true.
- Jasio is two years older than Małgosia.
- The mother is 24 years older than Jasio.
- Jasio and Małgosia together are 16 years younger than their father.
- Małgosia is twenty-four years younger than her father.
Draw a number line and mark on the number line point A whose coordinate is equal to 8. Next, mark on this line points B, C, D and E whose coordinates meet the following conditions:
- the coordinate of point B is three less than the coordinate of point A,
- the coordinate of the point Cis five greater than the coordinate of point B,
- the coordinate of point D is four greater than the coordinate of point C,
- the coordinate of point E o is ten less than the coordinate of point D.
Marcin has his collection of CDs with films. His collection includes 15 comedies, 5 documentary films, 8 historical films, 18 narrative films and 2 horror films.
Write in English how many more/how many fewer discs with films of a given type Marcin owns.
Compare CDs with:
a) comedies and historical films,
b) documentary films and narrative films,
c) historical films and horror films.
Indicate which pairs of expressions or words are translated correctly.
- o ile więcej - how many more
- o ile mniej - how many fewer
- liczba większa - greater number
- liczba mniejsza - less number
- porównywanie różnicowe - subtraction
- odejmowanie - addition
- how many more
- greater number
- o ile mniej
- o ile więcej
- less number
- liczba większa
- how many fewer
- liczba mniejsza
Glossary
dodawanie
Nagranie dostępne na portalu epodreczniki.pl
wymowa w języku angielskim: addition
liczba większa
Nagranie dostępne na portalu epodreczniki.pl
wymowa w języku angielskim: greater number
o ile mniej
Nagranie dostępne na portalu epodreczniki.pl
wymowa w języku angielskim: How many fewer
o ile więcej
Nagranie dostępne na portalu epodreczniki.pl
wymowa w języku angielskim: How many more
odejmowanie
Nagranie dostępne na portalu epodreczniki.pl
wymowa w języku angielskim: subtraction
Keywords
How many moreHow many more?
How many fewerHow many fewer?
greater numbergreater number
subtractionsubtraction