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NCERT · Ganita Prakash · Volume 1 · Chapter 5
Number Play
48 videos in this chapter
Number Play
48 videos
Chapter 5
Which Numbers Are Sums of Consecutive Numbers?
3:32
Which Numbers Are Sums of Consecutive Numbers?
You'll learn: Which Numbers Are Sums of Consecutive Numbers?
Chapter 5
Eight Ways to Place Plus and Minus Signs
3:25
Eight Ways to Place Plus and Minus Signs
You'll learn: Eight Ways to Place Plus and Minus Signs
Chapter 5
What Stays the Same in the Eight Expressions?
3:18
What Stays the Same in the Eight Expressions?
You'll learn: What Stays the Same in the Eight Expressions?
Chapter 5
Why Changing a Sign Does Not Change Parity
3:24
Why Changing a Sign Does Not Change Parity
You'll learn: Why Changing a Sign Does Not Change Parity
Chapter 5
One Parity Result, Two More Explanations
3:36
One Parity Result, Two More Explanations
You'll learn: One Parity Result, Two More Explanations
Chapter 5
Tell Whether an Expression Is Even Without Evaluating It
3:28
Tell Whether an Expression Is Even Without Evaluating It
You'll learn: Tell Whether an Expression Is Even Without Evaluating It
Chapter 5
Does an Algebraic Expression Always Give an Even Number?
3:20
Does an Algebraic Expression Always Give an Even Number?
You'll learn: Does an Algebraic Expression Always Give an Even Number?
Chapter 5
Two Types of Even Numbers
3:14
Two Types of Even Numbers
You'll learn: Two Types of Even Numbers
Chapter 5
When Do Two Even Numbers Add to a Multiple of Four?
3:12
When Do Two Even Numbers Add to a Multiple of Four?
You'll learn: When Do Two Even Numbers Add to a Multiple of Four?
Chapter 5
Add or Subtract Two Multiples
3:15
Add or Subtract Two Multiples
You'll learn: Add or Subtract Two Multiples
Chapter 5
A Divisible Sum Does Not Force Divisible Parts
3:24
A Divisible Sum Does Not Force Divisible Parts
You'll learn: A Divisible Sum Does Not Force Divisible Parts
Chapter 5
Multiples Keep Factors—but Not Every Larger Multiple
3:30
Multiples Keep Factors—but Not Every Larger Multiple
You'll learn: Multiples Keep Factors—but Not Every Larger Multiple
Chapter 5
When Do Two Divisibility Tests Combine?
3:29
When Do Two Divisibility Tests Combine?
You'll learn: When Do Two Divisibility Tests Combine?
Chapter 5
Can an Odd Plus an Even Be a Multiple of Six?
3:07
Can an Odd Plus an Even Be a Multiple of Six?
You'll learn: Can an Odd Plus an Even Be a Multiple of Six?
Chapter 5
One Remainder, Two Algebraic Descriptions
3:27
One Remainder, Two Algebraic Descriptions
You'll learn: One Remainder, Two Algebraic Descriptions
Chapter 5
Describe Consecutive Numbers With Letters
3:13
Describe Consecutive Numbers With Letters
You'll learn: Describe Consecutive Numbers With Letters
Chapter 5
Five Always, Sometimes or Never Challenges
3:29
Five Always, Sometimes or Never Challenges
You'll learn: Five Always, Sometimes or Never Challenges
Chapter 5
Find Numbers Satisfying Several Remainder Clues
3:29
Find Numbers Satisfying Several Remainder Clues
You'll learn: Find Numbers Satisfying Several Remainder Clues
Chapter 5
Add and Subtract Remainders
3:23
Add and Subtract Remainders
You'll learn: Add and Subtract Remainders
Chapter 5
Why Last Digits Test Divisibility by Two, Five and Ten
3:18
Why Last Digits Test Divisibility by Two, Five and Ten
You'll learn: Why Last Digits Test Divisibility by Two, Five and Ten
Chapter 5
Why the Last Two or Three Digits Are Enough
3:35
Why the Last Two or Three Digits Are Enough
You'll learn: Why the Last Two or Three Digits Are Enough
Chapter 5
Why the Digit Sum Reveals Divisibility by Nine
3:26
Why the Digit Sum Reveals Divisibility by Nine
You'll learn: Why the Digit Sum Reveals Divisibility by Nine
Chapter 5
Prove the Digit-Sum Test for Any Number
3:34
Prove the Digit-Sum Test for Any Number
You'll learn: Prove the Digit-Sum Test for Any Number
Chapter 5
Four Challenges With Multiples of Nine
3:39
Four Challenges With Multiples of Nine
You'll learn: Four Challenges With Multiples of Nine
Chapter 5
The Digit-Sum Test for Three
3:30
The Digit-Sum Test for Three
You'll learn: The Digit-Sum Test for Three
Chapter 5
Why Alternating Digit Sums Work for Eleven
3:31
Why Alternating Digit Sums Work for Eleven
You'll learn: Why Alternating Digit Sums Work for Eleven
Chapter 5
Use the Eleven Test and Find the Actual Remainder
3:37
Use the Eleven Test and Find the Actual Remainder
You'll learn: Use the Eleven Test and Find the Actual Remainder
Chapter 5
Complete the Divisibility Table Efficiently
3:31
Complete the Divisibility Table Efficiently
You'll learn: Complete the Divisibility Table Efficiently
Chapter 5
Why Two and Three Test Six, but Four and Six Do Not Test Twenty-Four
3:31
Why Two and Three Test Six, but Four and Six Do Not Test Twenty-Four
You'll learn: Why Two and Three Test Six, but Four and Six Do Not Test Twenty-Four
Chapter 5
Digital Root and Remainder Are Related, but Different
4:06
Digital Root and Remainder Are Related, but Different
You'll learn: Digital Root and Remainder Are Related, but Different
Chapter 5
Patterns in Digital Roots
3:37
Patterns in Digital Roots
You'll learn: Patterns in Digital Roots
Chapter 5
Predict Digital Roots Without Writing the Whole Number
3:32
Predict Digital Roots Without Writing the Whole Number
You'll learn: Predict Digital Roots Without Writing the Whole Number
Chapter 5
Solve Addition Cryptarithms by Following Carries
3:50
Solve Addition Cryptarithms by Following Carries
You'll learn: Solve Addition Cryptarithms by Following Carries
Chapter 5
Multiplication Cryptarithms: Bounds and Repeated Digits
3:26
Multiplication Cryptarithms: Bounds and Repeated Digits
You'll learn: Multiplication Cryptarithms: Bounds and Repeated Digits
Chapter 5
Solve BYE Times Six Equals RAY
3:18
Solve BYE Times Six Equals RAY
You'll learn: Solve BYE Times Six Equals RAY
Chapter 5
Three Cryptarithms With Tight Digit Constraints
3:26
Three Cryptarithms With Tight Digit Constraints
You'll learn: Three Cryptarithms With Tight Digit Constraints
Chapter 5
Repeated Digits in Multiplication Puzzles
3:24
Repeated Digits in Multiplication Puzzles
You'll learn: Repeated Digits in Multiplication Puzzles
Chapter 5
Find Missing Digits for Nine and Eighteen
3:09
Find Missing Digits for Nine and Eighteen
You'll learn: Find Missing Digits for Nine and Eighteen
Chapter 5
Two Remainder Claims That Need Careful Reasoning
3:22
Two Remainder Claims That Need Careful Reasoning
You'll learn: Two Remainder Claims That Need Careful Reasoning
Chapter 5
What Survives When Digits Are Reversed or Shuffled?
3:25
What Survives When Digits Are Reversed or Shuffled?
You'll learn: What Survives When Digits Are Reversed or Shuffled?
Chapter 5
Use Divisibility by Forty-Four to Find Two Digits
3:32
Use Divisibility by Forty-Four to Find Two Digits
You'll learn: Use Divisibility by Forty-Four to Find Two Digits
Chapter 5
Consecutive Multiples and an Interval Search
3:43
Consecutive Multiples and an Interval Search
You'll learn: Consecutive Multiples and an Interval Search
Chapter 5
Test Five More Claims About Multiples
3:29
Test Five More Claims About Multiples
You'll learn: Test Five More Claims About Multiples
Chapter 5
When Is a Sum of Three Numbers Divisible by Three?
3:30
When Is a Sum of Three Numbers Divisible by Three?
You'll learn: When Is a Sum of Three Numbers Divisible by Three?
Chapter 5
Products of Consecutive Integers
3:43
Products of Consecutive Integers
You'll learn: Products of Consecutive Integers
Chapter 5
The Final Two Multiplication Cryptarithms
4:03
The Final Two Multiplication Cryptarithms
You'll learn: The Final Two Multiplication Cryptarithms
Chapter 5
A Venn Diagram of Multiples—and the Rules Behind It
3:36
A Venn Diagram of Multiples—and the Rules Behind It
You'll learn: A Venn Diagram of Multiples—and the Rules Behind It
Chapter 5
Navakankari: Form Lines, Remove Pawns, Plan Ahead
3:51
Navakankari: Form Lines, Remove Pawns, Plan Ahead
You'll learn: Navakankari: Form Lines, Remove Pawns, Plan Ahead