# Lesson Notes By Weeks and Term - Junior Secondary School 1

BASIC OPERATIONS

SUBJECT: MATHEMATICS

CLASS:  JSS 1

DATE:

TERM: 2nd TERM

REFERENCE BOOKS

• New General Mathematics, Junior Secondary Schools Book 1
• Essential Mathematics for Junior Secondary Schools Book 1

WEEK SIX                                      Date:……………….

TOPIC: BASIC OPERATIONS

CONTENT:

• Addition of Numbers ( Place Values)
• Subtraction of Numbers ( Place Values)

The easiest method of adding or subtracting numbers is by having the knowledge of place value system. By this system of arrangement, all units ( U), Tens (T), Hundreds (H), Thousands ( T), and so, are vertically arranged in line. Note that numbers are written from right to left by their place values.

Example 1

Add the following numbers: 1092, 84, 8, 183.

Solution

 Th   H     T     U     1    9      9      2                   8      4  +                       8            1     8      3     2     2     6      7 MethodU = 2 + 4+ 8+ 3 = 17 ( write 7 under U and carry 1 to the T column)T = 9 + 8 + 8 + (1) = 26 ( write 4 and carry 2 to the H column)H = 0 + 1 + (1) = 2 ( write 2 under H and carry 1 to Th)Th = 1 + (1) = 2 ( write 2 under the Th)

Example 2

Ukachi has 1578 apples, jide has 682 apples and victor has 88 apples. How many apples do they have all together?

Solution

 TH     H     T     U   1      5     7      8 +        6     8      2                  8      8   2      3     4      8

Example 3

A man spent #2500 on housing, #1245 on savings, #3480 on feeding and #248 on the children’s education. How much did he spend altogether?

Solution

 TH     H      T     U 2        5      0      0 1        2      4      5 3        4      8      0           2      4      87         4      7      3

Evaluation:

1. Find the sum of 76,721, 2393, 184 and 96.
2. A man earned N73485.00 three years ago N 98472.00 a year ago and N124390.00 this year. How much altogether did he earn for the three years?

Subtraction of Numbers

Example 1

The sum of two numbers is equal to 67512. If one of the numbers is 24351, what is the second number?

Solution

 TTH     TH    H     T      U  6          7      5      1       2- 2          4      3      5       1  4          3      1      6       1

Evaluation:

1. There are 24 students in a class which comprises of 14 girls and 10 boys. If 5 girls and 3 boys were absent, how many students are present in the class?
2. Find the difference between 10342 and 2015

General Evaluation

1. A man borrowed N120 from a friend and borrowed N350 from his brother. How much is his total debt?
2. The temperature inside a room was recorded at 20oC and the temperature outside was measured as -8oC. How many degrees warmer was the room temperature more than the outside temperature?

Essential Mathematics for JSS1, pages 8 and 9

Weekend Assignment

1.By how many is 29 greater than 17? (a)12 (b)18 (c)19 (d)17

1. Simplify 79001- 73776 (a)105225 (b)5335 (c)5225 (d)5221
2. When you increase the sum of 345 and 1276 by 1453, the result will give (a)2074 (b)5023 (c)1453 (d)3074

4.There are 816 boys and 658 girls in a school. How many students are there altogether in the school? (a)1356 (b)1474 (c)1744 (d)1074

5.Find the difference between 8074 and 5729(a)2345 (b)5432 (c)5745 (d)4365

Theory

(1)The difference between two numbers is 603904.If the first number is 21432, what is the second number?

(2)Find the sum of the following numbers: 95,3, 2134, 93627, 18,  and 543.