New
New
Year 4

Explain the use of placeholders when multiplying whole numbers by 100

I can use place value to explain placing 2 0's after the final digit when we multiply whole numbers by 100

New
New
Year 4

Explain the use of placeholders when multiplying whole numbers by 100

I can use place value to explain placing 2 0's after the final digit when we multiply whole numbers by 100

Lesson details

Key learning points

  1. Multiples of 100 have zero in the tens and ones column.
  2. When a number is multiplied by one hundred the product is a multiple of one hundred.
  3. Multiplying by one hundred moves all the digits two columns to the left making the digits one hundred times the size.

Common misconception

Many pupils believe that 'adding 2 zeros' is multiplying by 100 which can lead to difficulties later on when they are introduced to decimal numbers.

Don't dismiss it. It's a pattern that has been spotted and generalised. Do encourage the children to work with physical resources that don't involve the numbers themselves so they can understand that it isn't adding zero but changing place value.

Keywords

  • Placeholder - A placeholder is where we use the digit 0 to hold a place in a number and maintain place value.

  • Magnitude - The magnitude of a number is its distance from 0

Make mistakes in the place value yourself whilst modelling and get the children to spot this. They will enjoy pointing out your mistakes! It helps them to firm up their error-spotting skills and consolidates their understanding.
Teacher tip

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).

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6 Questions

Q1.
What number is being represented using the Base 10 blocks?
An image in a quiz
Correct Answer: 131
Q2.
What number is being represented in the place value chart?
An image in a quiz
Correct Answer: 234
Q3.
What number is being represented using the place value counters?
An image in a quiz
Correct Answer: 222
Q4.
What number is being represented using the Base 10 blocks?
An image in a quiz
Correct Answer: 700
Q5.
What number is being represented in the place value chart?
An image in a quiz
Correct Answer: 6,632
Q6.
What number is being represented using the place value counters?
An image in a quiz
Correct Answer: 2,222

6 Questions

Q1.
Look at the image. The label below the arrow is missing a number. Complete it. times the size.
An image in a quiz
Correct Answer: 100
Q2.
Which of the following equations is represented by the place value counters and the arrow in the image?
An image in a quiz
Correct answer: 4 × 100 = 400
100 + 100 + 100 + 100 = 400
400 ÷ 100 = 4
Q3.
True or false? To multiply a whole number by 100, you just add two zeros.
True
Correct answer: False
Q4.
Which of the following equations is represented by the place value counters and the arrow in the image?
An image in a quiz
Correct answer: 12 × 100 = 1,200
12 + 1,000 = 1,012
1,200 ÷ 100 = 12
Q5.
What is the equation being represented in the place value chart showing before and after?
An image in a quiz
320 × 1 = 320
Correct answer: 32 × 100 = 3,200
5 + 5 = 10
3,200 ÷ 10 = 320
Q6.
Match the numbers with the numbers that are 100 times the size.
Correct Answer:6,600

600

Correct Answer:13,1,300

1,300

Correct Answer:27,2,700

2,700

Correct Answer:99,9,900

9,900