# Adding and subtracting/multiplying fractions

Good morning!
Schedule:
• Learning goals
• Last time
• Adding/subtracting fractions
• Multiplying fractions
• Work/practice
1 / 20
Slide 1: Slide
WiskundeMiddelbare schoolvwoLeerjaar 2

This lesson contains 20 slides, with interactive quizzes and text slides.

## Items in this lesson

Good morning!
Schedule:
• Learning goals
• Last time
• Adding/subtracting fractions
• Multiplying fractions
• Work/practice

#### Slide 1 -Slide

Learning goals
At the end of this lesson I can:
• add any fraction to another fraction
• subtract any fraction from another fraction
• Do multiplications with proper fractions
• Do multiplications with mixed numbers and improper fractions

Last time

21+63=
A
84
B
123
C
22

Equal fractions
21=63

#### Slide 5 -Slide

When am I allowed to add or subtract fractions?

#### Slide 6 -Open question

Adding/subtracting fractions
Same denominator!!

62+61=
31+92=
7583=

#### Slide 7 -Slide

Multiplying fractions

#### Slide 8 -Slide

Multiplying fractions
3152=3512=152
Numerator x numerator
Denominator x denominator

#### Slide 9 -Slide

Mixed numbers/whole numbers?

#### Slide 10 -Slide

What is the difference between multiplying and adding/subtracting fraction?

#### Slide 11 -Open question

Adding fractions
How can thinking about the context of a problem help you in
understanding the situation and what the question is asking you to solve? How can this
help you to determine a way to solve this problem?

Discuss with neighbour (2min)

#### Slide 12 -Slide

A school uses part of a field to create a rectangular area for the PTA carnival. They will partition the field so there are areas for games, food, and prizes. If      of the field is for prizes, and     of the field is for games, what fraction of the field is remaining for food?

How can the context/story of the problem help you solve it? what strategy would you use?
Discuss (5 min)
21
61

#### Slide 13 -Slide

A school uses part of a field to create a rectangular area for the PTA carnival. They will partition the field so there are areas for games, food, and prizes. If      of the field is for prizes, and     of the field is for games, what fraction of the field is remaining for food?

Think of a reasonable estimate for the answer to the question. Write this down on your mini-whiteboard.
Discuss (5 min)
21
61

#### Slide 14 -Slide

What do you think?
a. The answer is less than 1.
b. The answer is more than

c. The answer is less than

d. The answer is more than 0.
e. The answer is closer to 0 than
21
21
21

#### Slide 15 -Slide

Now find the exact answer to the problem:

#### Slide 17 -Slide

Adding/subtracting fractions
You changed 1/2 into 3/6
When you add 2 fractions you need to change them to make the denominators equal

https://www.geogebra.org/m/d4sq3jzx

#### Slide 18 -Slide

(Home)work
Worksheet on ManageBac: 1-10
p. 113 : 5H                1bfjcgk, 2aei, 3, 4be, 5

Finished? Challenge worksheet!
MyiMaths:
- adding and subtracting fractions

Challenge