Number Patterns

Lesson

When we write number sentences from word problems we need to pay attention to the important language in the word problem which will help us form our number sentence. There are certain words which will tell us which operation we need to use. In the following video i'll explain in more detail with addition and subtraction, with some simple multiplication in there too.

A frog took $6$6 jumps forward, then took $3$3 jumps back.

Which expression (number sentence) matches the word problem for the number of jumps the frog is from its starting point?

$0+6+3$0+6+3

A$0+6$0+6

B$0+6-3$0+6−3

C$0-3$0−3

D$0+6+3$0+6+3

A$0+6$0+6

B$0+6-3$0+6−3

C$0-3$0−3

D

The temperature on Monday was $24$24 degrees Celsius. The temperature dropped by $11$11 degrees on Tuesday and rose $2$2 degrees on Wednesday.

Which expression (number sentence) matches the word problem for the temperature on Wednesday?

$24+11-2$24+11−2

A$24-11+2$24−11+2

B$24-11-2$24−11−2

C$24+11+2$24+11+2

D$24+11-2$24+11−2

A$24-11+2$24−11+2

B$24-11-2$24−11−2

C$24+11+2$24+11+2

D

Sarah had $21$21 students in her class. Over the summer vacation $6$6 left the class, and when she returned there were $4$4 new students in her class.

Write a number sentence for the total amount of students in Sarah's class now.