You will discover the methods of multiplying mixed numbers.
Learning effect
You calculate the multiplication of a mixed number by a mixed number.
You do tasks using multiplication of fractions.
You use English to describe the method of multiplying common fractions.
Today you are going to learn the method of multiplying mixed numbers. Analyse the example below and think of methods of multiplying mixed numbers.
Check your hypothesis using the computer.
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Watch the slideshow to watch how you can multiply mixed numbers. What conclusion can you draw?
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Conclusion:
To multiply a mixed numbermixed numbermixed number, it should be converted into an improper fractionimproper fractionimproper fraction first.
Task 1
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Convert the mixed numbers to improper fractions and do the multiplication.
a)
b)
c)
Task 2
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Revise how to calculate the squares and the cubes of fractions. Use the same method.
a)
b)
c)
d)
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Conclusion:
The square of a mixed numbermixed numbermixed number is the productproductproduct of two identical mixed numbers.
The cube of a mixed numbermixed numbermixed number is the productproductproduct of three identical mixed numbers.
Task 3
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Ann wants to fence her flower‑bed in the shape of an equilateral triangle with the side of m. How many metres of the kerb does she have to buy? How much will she pay for the kerb, if the its running metre costs 15 PLN?
Task 4
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An extra task:
Peter says: „I thought of a number and multiplied it by . Then I multiplied the result by added and got . What number did Peter think of?
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Remember:
To multiply a mixed numbermixed numbermixed number, it should be converted into an improper fractionimproper fractionimproper fraction first.
The square of a mixed numbermixed numbermixed number is the productproductproduct of two identical mixed numbers.
The cube of a mixed numbermixed numbermixed number is the productproductproduct of three identical mixed numbers.
Check what you have learned by doing the following tasks.
Exercises
Exercise 1
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Exercise 2
Complete the task.
Calculate . Multiply the result by . Calculate of the number you have obtained.
4
Exercise 3
Ann and Chris together picked up of litre of blueberries. On their way home, they met Ann’s younger brother and gave him some fruit. He ate of the picked blueberries. How much blueberries did the children bring home?
Describe the method of multiplication of mixed numbers in English.
of a litre
Exercise 4
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Glossary
common fraction
common fraction
ułamek zwykły
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mixed number
mixed number
liczba mieszana
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natural number
natural number
liczba naturalna
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reducible fractions
reducible fractions
ułamek skracalny – ułamek, który można skrócić
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improper fraction
improper fraction
ułamek niewłaściwy – ułamek, którego licznik jest większy lub równy mianownikowi