Mastering Multiplication and Division
Mastering Multiplication and Division
Items in this lesson
Mastering Multiplication and Division
What do you already know about multiplying and dividing one- and two-digit numbers?
Learning Objective
At the end of the lesson you will be able to multiply and divide one- and two-digit numbers with confidence using different strategies.
What are Multiplication and Division?
Multiplication is repeated addition. Division is splitting into equal groups. These are opposite operations.
Multiplication as Equal Groups
For example: 3 × 4 means 3 groups of 4. Total is 12 objects.
Multiplication on a Number Line
Use a number line to skip count by 3, four times: 0, 3, 6, 9, 12.
Simple Multiplication Example
What is 7 × 2? Think: 7 + 7 = 14. The answer is 14.
Multiplication Patterns
Spotting a pattern makes it easier to remember and solve.
2s: Add 2 each time. 5s: End in 0 or 5. 10s: End in 0.
Why are Patterns Helpful?
Times Table Quick Facts
Multiplying with Two-Digit Numbers
To multiply 12 × 3, separate to (10 × 3) + (2 × 3) = 30 + 6 = 36.
Example: 24 × 2
Break into 20 × 2 = 40 and 4 × 2 = 8. 40 + 8 = 48.
Practice: Multiplication
Try: 13 × 4. Hint: (10 × 4) + (3 × 4) Answer: 40 + 12 = 52.
Division as Sharing
Division breaks things into equal groups. Example: 12 ÷ 3 means share 12 sweets between 3 people.
Division on a Number Line
Go backwards in jumps of divisor. 12 ÷ 3 is four jumps of 3: 12, 9, 6, 3, 0.
Quick Division Example
15 ÷ 5 = 3, because 5 + 5 + 5 = 15, so 3 groups.
Division Vocabulary
Dividend ÷ Divisor = Quotient. E.g. 20 ÷ 4 = 5, 20 is dividend, 4 is divisor, 5 is quotient.
Division Example with Remainder
14 ÷ 4 = 3 remainder 2, because 4 × 3 = 12, and 2 left. Not always even shares.
Dividing Two-Digit Numbers
36 ÷ 6 = 6. Think: How many sixes make 36? Multiplication fact helps!
Multiplication vs. Division
Multiplication
Division
Joins equal groups together. 5 × 2 = 10.
Splits a total into equal groups. 10 ÷ 2 = 5.
Check with Inverse Operations
Use multiplication to check division answers and vice versa! 8 × 5 = 40 so 40 ÷ 8 = 5.
Practice: Division
Try: 48 ÷ 6. Think: 6 × ? = 48 Answer: 8.
Well Done! Time to Practise More!
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