1) To calculate the average of up to five numbers, add up all the numbers and divide the total by the number of numbers. 2) Solving problems involving averages requires calculating the total from the average and number of data points, and using subtraction to determine missing values. 3) For example, if the average of 5 days of fruit sales is 35 fruits and the total sold is 140 fruits, multiplying the average by 5 gives the total of 175 fruits. Subtracting the known total of 140 fruits from 175 gives the number sold on the missing day, which is 35 fruits.

1. Learning Outcomes
Calculate the average of up to five numbers
Total of numbers
Average =
Quantity of numbers
2. Solve problems in real contexts
involving average

2. Calculate the average of up to five numbers
Example 1 :
Find the average for the numbers given
8, 9, 12 and 7
Calculate the
total in
vertical form Step 1 :
8
9
12
+ 7
Divide the 36
answer by 4
Step 2 : Average = Total of numbers
Quantity of numbers
36
4
Solve by
long division
09
Step 3 : 4 36
0
36
36
0
Write the
answer
9

3. Solve problems in real contexts involving average
Example 1 :
Table 1 shows the number of fruits sold by Salleh’s shop
in five days
DaysNumber of
FruitsMonday35Tuesday45WednesdayThursday30Frida
y40Table 1
The average number of fruits sold in five days is 35
fruits. What is the number of fruits sold on Wednesday?.
Understanding Step 1 :
the problem 1. Average = 35 fruits.
2. Number of days = 5
3. Total fruits given:
35 + 45 + 30 + 40 = 140
4. Find the number of fruits
sold on Wednesday
Remember :
Total = Average × Quantity of numbers
Multiply the
Step 1 : Find the total average by the
quantity of
35 × 5 days = 175 numbers
Substract the Step 2 :
multiplication 175 - 140 = 35
answers by the
total fruits given.
35 fruits
Write the
answer