Scaling
If one ribbon is 35 cm long, 4 ribbons are 4 times as long.
Scaling means making a quantity several times larger.
Year 5
Solve problems involving multiplication and division, including scaling and correspondence problems
Solve multiplication and division problems, including scaling and correspondence situations.
Lesson overview
Number - multiplication and division
Multiplication and division can appear in many forms. Sometimes we are finding equal groups, sometimes we are scaling one amount, and sometimes we are counting all possible combinations in a correspondence problem.
Grouping
156 books shared onto 6 shelves means 156 / 6 on each shelf.
Division can show how many go into each equal group.
Correspondence
3 shirts with 4 ties gives 12 possible outfits.
Each item in one set matches with every item in the other set.
Worked example
A shop packs 24 pencils into each box. How many pencils are in 13 boxes?
- Each box has the same number of pencils.
- Multiply 24 by 13.
- 10 boxes hold 240 pencils and 3 boxes hold 72 pencils.
- The total is 312 pencils.
Round 1: Learn it
Decide whether the problem is grouping, scaling or correspondence before you calculate.
Finish this round to unlock Round 2: Show you know it.
Question 1
A ribbon is 35 cm long. How long are 4 ribbons?
Question 2
156 books are shared equally onto 6 shelves. How many on each shelf?
Question 3
A shop packs 24 pencils into each box. How many pencils are in 13 boxes?
Question 4
How many outfits can be made from 3 shirts and 4 ties?
Question 5
Which operation fits this problem best: 8 packets with 25 stickers in each packet?
Common mistakes
Watch for these as you work through the lesson.
- Using addition when the problem describes equal groups.
- Missing the idea of every possible combination in correspondence problems.
- Choosing division when the problem is asking for a total.
Related topics
These ideas connect closely to this lesson.
- Multiply numbers up to 4 digits by a one- or two-digit number using a formal written method, including long multiplication for two-digit numbers.
- Divide numbers up to 4 digits by a one-digit number using the formal written method of short division and interpret remainders appropriately.