Introduction
Year 5 Large Number Multiplication
Task
Students will use the following seven lessons to solve a Harry Potter Riddle.
Lesson 1 - students will learn to round to one significant figure
Lesson 2 - students will learn single digit multiplication, exploring factors and multiples using number sequences.
Lesson 3 - students will learn how to multiply by 10's, 100's and 1000's, exploring factors and multiples using number sequences.
Lesson 4 - students will learn estimation, using calculators to check the reasonableness of answers.
Lesson 5 - students will learn how to multiply single digit numbers by large numbers, using calculators to check the reasonableness of answers.
Lesson 6 - students will learn how to multiply by two digit numbers, using calculators to check the reasonableness of answers.
Lesson 7 - students will learn how to multiply two digit numbers by large numbers, using calculators to check the reasonableness of answers.
Process
Question: What is Lord Voldermort's wand made out of?
Answer:
| 10 | 1872 | 1000 | 1000 | 2000 | 2884 | 42 | 3500 | 4085 | 42 | 1872 | 122,958 | 100,000 |
| 2000 | 8000 | 72 | 1872 | 3500 | 2884 | 42 | 1872 | 137,598 | 2982 | 122,958 | 137,598 | 1872 |
Lesson 1 - Rounding to one significant figure
Harry is swamped and cant find his way out of significant figures. He needs your help! He has given you a game to play to practice, then you have two questions on your worksheet that will help to solve the riddle.
Question: Round these numbers to one significant figure.
1) 14 = ___ Y 2) 1524 = _____ I
Lesson 2 - Single Digit Multiplication
Harry is so close to finding the sorcerers stone. You must practice the game below to be ready for the next two tricky questions on your worksheet, good luck!
http://www.softschools.com/math/games/multiplication_games/
Question: Complete the following single digit multiplications
3) 7 x 6 = ___ H 4) 8 x 9 = ___ F
Lesson 3 - Multiplying by 10's, 100's and 1000s
Thank you for helping Harry find the Sorcerers Stone, now Harry, Hermione and Ron need your help in the Chamber of Secrets. Play this game and help Harry unlock another clue.
Question: Compelte the following mutliplications
5) 10 x 100 = ____ W 6) 100 x 1000 = ______ N
Lesson 4 - Estimation
You made it out of the Chamber alive, and have unlocked another clue. Harry needs your help with the Prisioner of Azkaban. Only a few more clues to gather before you and Harry can crack the code.
http://www.abcya.com/estimating.htm
Question: Estimate the following number by using one significant figure.
7) 5 x 745 = _____ A 8) 8 x 978 = ______ X
Lesson 5 - Multiplying single digit numbers by large numbers
Harry has lost his glasses and cant read the multiplication sums. Help Harry answer the sums to unlock the next piece of the puzzle.
http://www.math-play.com/Multiplicaton-Jeopardy/multiplication-game.html
Question: Complete the following mutliplications
9) 7 x 426 = ____ C 10) 4 x 721 = _____ T
Lesson 6 - Multiplying by two digit numbers
Harry has broken his wand, help Harry fight his way out of the forest by solving these multiplication problems.
http://www.kidsmathtv.com/learn/multiply-2-by-2-digit-numbers-game-for-4th-grade-monster-board-game/
Question: Complete the following two digit multiplications
11) 26 x 72 = _______ E 12) 43 x 95 = ________ P
Lesson 7 - Multiplying large numbers by two digit numbers
Help Harry defeat Voldermort once and for all. This is the last activity Harry needs you to complete. Good luck.
https://www.ixl.com/math/grade-5/multiply-by-3-digit-numbers
Question: Complete the large number multiplications
13) 426 x 323 = ____ R 14) 621 x 198 = _____ O
Evaluation
This is how your work will be evaluated.
reasoning includes investigating strategies to perform calculations efficiently, continuing patterns involving fractions and decimals, interpreting results of chance experiments, posing appropriate questions for data investigations and interpreting data sets.
| Criteria | Above Level (Year 6) | At Level (Year 5) | Below Level (Year 4) |
| Reasonableness of results | Students connect fractions, decimals and percentages as different representations of the same number. | Students check the reasonableness of answers using estimation and rounding | They continue number sequences involving multiples of single digit numbers. |
| Able to identify and describe numbers | They describe the use of integers in everyday contexts. | Students identify and describe factors and multiples | They describe number patterns resulting from multiplication |
| Using all four operations | Students make connections between the powers of 10 and the multiplication and division of decimals | Students identify and explain strategies for finding unknown quantities in number sentences involving the four operations | They identify and explain strategies for finding unknown quantities in number sentences |
| Strategies within the four operations | They add, subtract and multiply decimals and divide decimals where the result is rational. | Students solve simple problems involving the four operations using a range of strategies | They recall multiplication facts to 10 x 10 and related division facts. |
Conclusion
The Goal
The overall goal of this learning sequence was to get students to multiply two digit numbers by large numbers.
To achieve the end goal, students first learnt how to round, then single and two digit multiplication, and finally moved to large digit multiplication.
The aim of this sequence of learning is for the students to learn maths in a fun environment involving digital technologies.
Credits
The author did not create any of the activities and would like to acknowledge the following websites for use of their resources:
- ACARA Website
- Mathopolis.com
- Softschools.com
- Learninggamesforkids.com
- Abcya.com
- Math-play.com
- Kidsmathtv.com
- ixl.com
Teacher Page
Australian Curriculum Descriptor - Year 5
Solve problems involving multiplication of large numbers by one- or two-digit numbers using efficient mental, written strategies and appropriate digital technologies (ACMNA100)
Prior Knowledge
Investigate number sequences involving multiples of 3, 4, 6, 7, 8, and 9 (ACMNA074)
Recall multiplication facts up to 10 × 10 and related division facts (ACMNA075)
Develop efficient mental and written strategies and use appropriate digital technologies for multiplication and for division where there is no remainder (ACMNA076)
Lesson Outcomes
Lesson 1 - students will learn to round to one significant figure, exploring factors and multiples using number sequences.
Lesson 2 - students will learn single digit multiplication, exploring factors and multiples using number sequences.
Lesson 3 - students will learn how to multiply by 10's, 100's and 1000's, exploring factors and multiples using number sequences.
Lesson 4 - students will learn estimation, using calculators to check the reasonableness of answers.
Lesson 5 - students will learn how to multiply single digit numbers by large numbers, using calculators to check the reasonableness of answers.
Lesson 6 - students will learn how to multiply by two digit numbers, using calculators to check the reasonableness of answers.
Lesson 7 - students will learn how to multiply two digit numbers by large numbers, using calculators to check the reasonableness of answers.
Adressing the Proficiency Strands
By students completing the chosen activities and solving the Harry Potter riddle the teacher will be able to assess the student as above level, at level or below level.
At Level
Year 5 - Solve problems involving multiplication of large numbers by one- or two-digit numbers using efficient mental, written strategies and appropriate digital technologies (ACMNA100)
- exploring techniques for multiplication such as the area model, the Italian lattice method or the partitioning of numbers
- applying the distributive law and using arrays to model multiplication and explain calculation strategies
Below Level
Year 4 -
Investigate number sequences involving multiples of 3, 4, 6, 7, 8, and 9 (ACMNA074)
- recognising that number sequences can be extended indefinitely, and determining any patterns in the sequences
Recall multiplication facts up to 10 × 10 and related division facts (ACMNA075)
- using known multiplication facts to calculate related division facts
Develop efficient mental and written strategies and use appropriate digital technologies for multiplication and for division where there is no remainder (ACMNA076)
- using known facts and strategies, such as commutativity, doubling and halving for multiplication, and connecting division to multiplication when there is no remainder
Above Level
Year 6 -
Multiply decimals by whole numbers and perform divisions by non-zero whole numbers where the results are terminating decimals, with and without digital technologies (ACMNA129)
- interpreting the results of calculations to provide an answer appropriate to the context
Multiply and divide decimals by powers of 10 (ACMNA130)
- multiplying and dividing decimals by multiples of powers of 10
The Evaluation is taken directly from the ACARA Website to show the at level, above level and below level criterias.
Please see Evaluation for them in use.