New
New
Year 1

# Solve subtraction problems using knowledge of 10 and a bit

I can solve subtraction problems using knowledge of 10 and a bit in different contexts.

New
New
Year 1

# Solve subtraction problems using knowledge of 10 and a bit

I can solve subtraction problems using knowledge of 10 and a bit in different contexts.

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## Lesson details

### Key learning points

1. The teens numbers can be represented as ten and a bit.
2. We can solve addition and subtraction problems with the ones part or tens part missing.
3. A part-part whole model can help to represent the missing whole or missing parts.

### Common misconception

Pupils do not connect a known partition of a teen number e.g. 16 is 1 ten and 6 ones to a subtraction or addition context and therefore use a less efficient strategy.

Practical experiences using a group of 10 and ones are key to supporting understanding that the partitioning structure can work for different contexts.

### Keywords

• Partition - The act of splitting an object or value down into smaller parts.

• Whole - All of a group or number.

• Part - A piece or section of the whole.

### Licence

This content is © Oak National Academy Limited (2024), licensed on Open Government Licence version 3.0 except where otherwise stated. See Oak's terms & conditions (Collection 2).

## Starter quiz

### 6 Questions

Q1.
What is the missing whole?
Q2.
What is the missing part?
Q3.
Which equation matches the part-part-whole model?
Correct answer: 10 + 3 = 13
10 + 13 = 3
10 = 13 + 3
Correct answer: 3 + 10 = 13
Q4.
Jacob is going to hop 9 times. He has already hopped 5 times. How many more hops does he need to do?
Q5.
Izzy is going to jump 10 times across the playground. She has jumped 6 times. How many more jumps does she need to do?
Q6.
What is the missing part in the part-part-whole model?

## Exit quiz

### 6 Questions

Q1.
Jacob and Laura have collected 13 sticks at the park. Laura has 3 sticks. Jacob has dropped his sticks. How many did he drop?
Q2.
Which part-part-whole model matches this problem? Jacob collected some stones. He collected 15 stones but lost 5 of them. How many did he have left?
Correct Answer: An image in a quiz
Q3.
Which of these equations can be represented by this bar model?
10 + 14 = ___
Correct answer: 14 − 10 = ___
10 − 14 = ___
Q4.
Jacob and Laura collected 19 stones. 10 are brown and the rest are grey. How many are grey? Which equation matches this problem?
19 + 10 = ___
Correct answer: 19 − 10 = ___
10 − 19 = ___
Q5.
Jacob had some cubes. Laura took 8 and he has 10 left. How many cubes did he have at the start? Which equation with a missing number correctly matches this problem?
Correct answer: ___ − 8 = 10
10 − 2 = ___
10 − ___ = 8
Q6.
Laura has red, blue and yellow marbles. There are 17 marbles in total. 3 marbles are red and 7 marbles are blue. How many are yellow?