The result of subtracting one number from another. How much one number differs from another.

Use number facts to solve problems in measures and data contexts

Maths

In this unit pupils will add and subtract 1s and 10s from 2 digit numbers. They will use number facts to add/subtract a single-digit number to/from a 2-digit number. They will use a part-part-whole model to represent addition and subtraction. In the future unit pupils will learn to find 10 more or less than a 2-digit number They will  add and subtract 10 to/from a 2-digit number using number facts

In the prior unit pupils added 3 addends. They used strategies such as finding 2 addends to total 10 or 2 numbers to bridge though 10. In this unit pupils will add and subtract 1s and 10s from 2 digit numbers. They will use number facts to add/subtract a single-digit number to/from a 2-digit number. They will use a part-part-whole model to represent addition and subtraction.

Adding and subtracting ones and tens to and from 2-digit numbers

Choose the bar model that correctly represents this problem. Sam built a tower that was 33 cm tall. Alex built a taller tower. The difference between them was 2 cm. How tall was Alex’s tower?

Which known fact would you use to solve the problem below? Sam built a tower that was 39 cm tall and Alex built one that was shorter. The difference between them was 4 cm. How tall was Alex’s tower?

Which equation could represent the problem shown? Alex spent 46 p and Sam spent 49 p. What is the difference between the amounts they spent? 

Use the bar chart to answer the question below.  What is the difference in height between Sofia’s sunflower and Alex’s sunflower? {{ }} cm

Use the bar chart to answer the question below. Which known fact would help you solve it? Sam’s sunflower grew 3 cm in the next week. How tall was it now?

Which known fact could you use to solve this problem? Izzy’s sunflower was 27 cm tall and Jun’s was 22 cm tall. What was the difference between the heights of their sunflowers?

There were 72 children in the hall and 5 in the classroom.
How many children were there altogether?
Which part-part-whole model would represent this problem?

Sam spent 86 p altogether on an ice-cream and some sprinkles. The sprinkles cost 5 p. How much did the ice-cream cost?
Which known fact will help you solve the problem?

Which known fact would you use to solve the problem shown below? There were some cars. 3 were red and 51 weren’t red. How many cars were in the car park?

Choose the known fact that would help solve this problem. I had some books on the shelf. 72 fell off, so there were 3 left. How many books were there on the shelf to start with?

Choose the known fact that would help to solve this problem. Sam spent 45 p and Alex spent less than Sam. The difference between the amounts spent was 3 p.  How much did Alex spend? 

Choose the known fact that would help to solve this problem. Alex had 49 shells. 5 were brown and the rest were white. How many were white?

This lesson will soon be taken down.

Use number facts to solve problems in measures and data contexts

Lesson outcome