Basic Operation JSS1 Mathematics Lesson Note

 Adding and Subtracting

When adding or subtracting numbers, make sure you know the place values of the numbers. Then write each number underneath the other so that the units (U) figures are in line, all the tens (T), all the hundreds (H), and so on are in line.

Example 1:

1. Add 1952 and 567
2. Take away 936 from 7093
3. Ade has 5673 marbles, Ola has 3426 marbles, and Michael has 887 marbles. How many marbles do they have altogether?
4. Find the total of 90156, 300673, and 65489.
5. The difference between the two numbers is 6032. If the larger number is    96005, what is the smaller number?

Note: remember to write the numbers underneath.

Solution:

1. 1 9 5 2 + 5 6 7 = TH  H  T  U

           1  9  5  2

             +5  6  7

2  5  1  9

2.       TH  H  T  U

7   0  9  3

  -9  3  6

6  1  5  7

3.       TH  H  T  U

Ade s MARBLES           5  6  7  3

Olu’s MARBLES             3  4  2  6

Michael’s MARBLES          8  8  7

ALTOGETHER                 9  9  8  6 

4    H.TH   T.TH    TH    H   T   U

          3        0           0    6   7   3

                    9           0    1   5   6

                  +6           5    4   8  9

         4         5          6    3   1  8

5.

T.TH    TH    H   T   U

 9        6     0    0   5

6     0    3   2

8        9     9    7   3

EVALUATION: 

1. Find the total of 453323, 642176, 99510
2. Take away 301653 from 887321
3. Find the sum of 666721, 55432, 29255, 387, 554, and 77
4. Michael collected 1350 oranges from her sister Helen. He gave 546 to Mathew and 123 to Kenny. How many oranges are left in Michael’s hands?

Multiplication and Division Of Numbers

Example:

1. Find the product of 8600 and 150

Ii. A big company recently bought 78 new computers, each costing ₦95,000. How much did the company spend?

Iii. Divide 15648 by 12

Iv. 5982 computers are to be shared among 40 schools. How many will each school get, and how many will be left over?

Solution:

        8     6     0     0

         X     1     5     0

         0     0     0     0

  4     3     0     0     0    

   8     6      0      0                   

1     2     9     0      0     0    0 

2.     9     5     0     0     0

    x                          7     8

    7      6     0     0     0     0

6     6     5     0     0     0     0

 6    7      2     6     0     0     0     0     

3. 12       1   5    6    4    8

           1     3     0     4

            1 2

            36

            36     

            48            

4. 40       5  9  8  2

149

      4  0

           1  9  8

1  6  0

           3  8  2

3 6 0 

2  2

Note: Each school will collect 149 computers, and the leftovers will be 22.

EXERCISE:

1. Multiply the following: (a) 6745 by 356 (b) 89760 by 120
2. Find the product of 98700 and 4900
3. Divide the following: (a) 56748 by 24 and (b) 640000 by 80
4. 789 oranges are to be shared equally among 14 brothers. How many will each person get, and how many will remain?