Number Info for

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Count the number of tens:

4 tens

Add up Ten-Groups

Ten-Groups = 10 + 10 + 10 + 10

Ten-Groups = 40

Count the number of ones:

5 ones

Add this to the ones for our total:

45 = 0 Hundreds + 40 Tens + 5 ones

45 = 0 + 40 + 5

Show numerical properties of 45

45

Draw this point on a number line:

Word Notation for 45

forty five

Write the number 45 in expanded notation form:

Decompose 45

Express in powers of 10

Each digit in the whole number represents a power of 10:

Take the whole number portion on the left side of the decimal

Build Expanded Notation with powers of 10

Expanded Notation of 45 = (4 x 10¹) + (5 x 10⁰)

Expanded Notation of 45 = (4 x 10) + (5 x 1)

Prove this is the correct notation:

45 = 40 + 5

45 = 45 <---- Correct!

Tally Marks for 45

Make blocks of 5

Tally Marks Definition:

1 tally mark = |

2 tally marks = ||

3 tally marks = |||

4 tally marks = ||||

5 tally marks = | | | |

9 blocks of 5 and 0 left over

5 = | | | |

10 = | | | |

15 = | | | |

20 = | | | |

25 = | | | |

30 = | | | |

35 = | | | |

40 = | | | |

45 = | | | |

Tallies for 45

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Ordinal for 45

Define an ordinal number

A position in a list

45th

Digit and Reduced Digit Sum for 45

Calculate the digit sum of 45

Calculate the reduced digit sum of 45

Add up 2 digits of 45:

Digit Sum → 4 + 5 = 9

Since our digit sum ≤ 9:
we have our reduced digit sum

Digit Sum → 4 + 5 = 9

Digit Product for 45:

Calculate the digit product of 45

Digit Product = Value when you multiply
all the digits of a number together.

We multiply the 2 digits of 45 together

Digit product of 45 = 4 * 5

Digit product of 45 = 20

Opposite of 45

Opposite of 45 = -(45)

Opposite of = -45

Place Value for 45

Place value describes each digit

Whole Number Position 2: 45

4 is our tens digit

This means we have 4 sets of tens

Whole Number Position 1: 45

5 is our ones digit

This means we have 5 sets of ones

4 is our tens digit
5 is our ones digit

Natural Logarithm of 45

When e^y = x and e = 2.718281828459
We have Ln(x) = log_e(x) = y

Evaluate x = 45

Ln(45) = log_e(45) = 3.8066624897703

Is 45 divisible by:

2,3,4,5,6,7,8,9,10,11

Divisibililty Check for 2

Last digit ends in 0,2,4,6,8

The last digit of 45 is 5

Since 5 is not equal to 0,2,4,6,8:
then 45 is not divisible by 2

Divisibililty Check for 3

Sum of the digits is divisible by 3

The sum of the digits for 45 is 4 + 5 = 9

Since 9 is divisible by 3:
Then 45 is divisible by 3

Divisibililty Check for 4

Take the last two digits
Are they divisible by 4?

The last 2 digits of 45 are 45

Since 45 is not divisible by 4:
Then 45 is not divisible by 4

Divisibililty Check for 5

Number ends with a 0 or 5

The last digit of 45 is 5

Since 5 is equal to 0 or 5:
Then 45 is divisible by 5

Divisibililty Check for 6

Divisible by both 2 and 3

Since 45 is not divisible by 2 and 3:
Then 45 is not divisible by 6

Divisibililty Check for 7

Multiply each respective digit by 1,3,2,6,4,5
Work backwards
Repeat as necessary

5(1) + 4(3) = 18

Since 18 is not divisible by 7:
Then 45 is not divisible by 7

Divisibililty Check for 8

Take the last three digits
Are they divisible by 8

The last 2 digits of 45 are 45

Since 45 is not divisible by 8:
Then 45 is not divisible by 8

Divisibililty Check for 9

Sum of digits divisible by 9

The sum of the digits for 45 is 4 + 5 = 9

Since 9 is divisible by 9:
Then 45 is divisible by 9

Divisibililty Check for 10

Ends with a 0

The last digit of 45 is 5

Since 5 is not equal to 0:
Then 45 is not divisible by 10

Divisibililty Check for 11

Σ odd digits - Σ even digits = 0
or 45 is a multiple of 11

Sum the odd digits:

45

4

Odd Sum = 4

Sum the even digits:

45

5

Even Sum = 5

Take the difference:

Δ = Odd Sum - Even Sum

Δ = 4 - 5

Δ = -1

Divisibility Check:

Because Δ / 11 = 4.0909090909091:
Then 45 is NOT divisible by 11

Divisibility Final Answer

45 is divisible by
(3,5,9)

Final Answer

Tags:

• integer
• number
• property
• tally