## Elementary Math (K-6th) Tutorial

#### 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 