## Elementary Math (K-6th) Tutorial

*DEVELOPMENT OF NUMBERS*

#### Intro

Mathematics began when people started to count and measure.Counting and measuring are part of everyday life.Every language in the world contains words for numbers and measures.People have always used their figures to help them when counting which lead to collecting in groups.When numbers are group in tens , the system of counting is known as a BASE TEN method of counting.Most people use base ten when counting . For this reason , base ten is used internationally.It should also be noted that the counting of ordinary numbers is done in base ten.

#### Sample Problem

TYPES OF SYSTEM OF COUNTING

There are different system of counting which are :

1. DAYS SYSTEM OF COUNTING : In this system of counting , we are concern with days , weeks , months , etc.

NOTE : 7 days = 1 week

4 weeks = 1 month

12 month = 1 year

52 weeks = 1 year

365 days = 1 year

366 days = 1 leap year

13 lunar months = 1 year

2. TIME SYSTEM OF COUNTING :This system of counting is concern with the time such as second,minute,hour,etc.

NOTE : 60 seconds = 1 minute

60 minutes = 1 hour

24 hours = 1 day

2. ROMAN NUMERAL SYSTEM

Roman numeral system are numeral of the ancient rome based on the letters of the alphabet to give a sum.

In Roman numeral system

I stands for unit , X for tens , C for hundreds , V for fives , etc .The table below shows how the letters are used ;

EUROPEAN NUMBERS ROMAN NUMBERS

1 I

2 II

3 III

4 IV

5 V

6 VI

7 VII

8 VIII

9 IX

10 X

11 XI

20 XX

40 XL

50 L

90 XC

100 C

500 D

1000 M

400 CD

900 CM

RULES FOR ROMAN NUMERAL SYSTEM

RULE 1 :Whenever a small value roman numeral come before a large value roman number , SUBTRACT to get the value of the combined roman figures.

E.g IV = 5 – 1 =4 ,

IX = 10 – 1 = 9 ,

XL = 50 – 10 = 40 ,

XC = 100 – 10

CD = 500 – 100 = 400

CM = 1000 – 100 = 900

IM = 1000 – 1 = 999

XM = 1000 – 10 = 990

RULE 2 : Whenever a large value roman number come before a small roman number , ADD to get the value of the combined roman figures.

E.g VI = 5 + 1 = 6

XV = 10 + 5 = 15

CII = 100 + 2 = 102

MXX = 1000 + 20 = 1020

DCC = 500 + 200 = 700

MC = 1000 + 100 = 1100

CL = 100 + 50 = 150

RULE 3 : Locate small value before large value roman numeral before solving or simplifying the roman numeral.

#### Solution

EXAMPLE 1 : Find the total of 1 week 5 days , 6 days and 3 weeks 4 days .

wk day

1 5

6 total = 6 weeks 1 day

+ 3 4

= 6 1

EXAMPLE 2 : A baby is 5 weeks and 6 days old .what is the baby s age in days ?

Baby s age = 5 weeks + 6 days

= ( 5 x 7 days ) + 6 days

= 35 days + 6 days

= 41 days

Therefore, The baby is 41 days old

EXAMPLE 3 ; Find the number of seconds in 4 minutes 49 seconds

4 minutes 49 seconds = 4 min + 49 sec

= ( 4 x 60 sec ) + 49 sec

= 240 sec + 49 sec

= 289 sec

The total number of seconds is 289.

EXAMPLE 4 : Add the following time together ,give the answer in hours and minutes : 2 hr 25 min , 3 hr 40 min 28 min and 1 hr 35 min

HR MIN

2 25

3 40

28

+ 1 35

= 8 8

Therefore, the total time is 8 hrs 8 min.

EXAMPLE 6 : Find the number that the following roman numerals represent (a.) CCCXC (b.) DIX

(a.) CCCXC = CCC + XC (b.) DIX = D + IX

= 300 + 90 = 500 + 9

= 390 = 509

EXAMPLE 7 : Write the following numbers in roman numerals (a.) 2016 (b.) 3472

(a.) 2016 = 2000 + 16 (b.) 3472 = 3000 + 400 + 70 + 2

= MM + XVI = MMM + CD + LXX + II

= MMXVI = MMMCDLXXII

# About The Author

Math Expert |

My name is Fasesin James Opeyemi.I am a christain from nigeria based in lagos .i finished from YABA COLLEGE OF TECHNOLOGY ,YABA,LAGOS,NIGERIA.There i study electrical/electronics engineering.I started my teaching career in the year 2000 with MERIT COMPREHENSIVE COLLEGE,JAKANDE ESTATE,LAGOS.I Joined ... |

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