Number sentences with fractions
You may have already looked at representing and comparing fractions as areas. You may also have looked at how to write number sentences from stories with whole numbers. Remember that we can look for key words to tell us what operator to use.
Now watch this video to look at representing fractions with number sentences.
Once you've written a number sentence, you can solve it to find the final answer. For example, you may need to add or subtract the fractions.
Underline the key words to help understand the mathematics in the story.
A number sentence is a way to represent the mathematics with symbols.
Worked Examples
Question 1
Hannah had climbed one seventh of the ladder to the roof when she realised she'd forgotten her phone, so went back down to get it.
Complete the number sentence that describes how far in total Hannah has climbed once she has returned to the bottom of the ladder.
Hannah has climbed $\editable{}$ seventh plus $\editable{}$ seventh of the length of the ladder.
Question 2
Which of the following scenarios fits the number sentence:
"Bob is now $15$15 nineteenths minus $7$7 nineteenths of a kilometre away from where he started."
Bob walked fifteen nineteenths of a kilometre, rested and then walked seven nineteenths of a kilometre back.
ABob walked fifteen nineteenths of a kilometre, rested and then walked seven nineteenths of a kilometre further.
BBob walked seven nineteenths of a kilometre, rested and then walked fifteen nineteenths of a kilometre back.
CBob walked fifteen nineteenths of a kilometre, rested and then walked one nineteenth of a kilometre back.
D
Question 3
Lachlan throws a ball and it hits the ground four elevenths of a metre away from him. The ball then rolls a further twelve elevenths of a metre away and stops.
Complete the number sentence that describes how far away the ball is from Lachlan.
The ball is $\frac{\editable{}}{\editable{}}+\frac{\editable{}}{\editable{}}$+ of a metre away from Lachlan.