96
Subtracting a mixed number from a whole number
Textbook: Part 3, lesson 96, pp. 78–80
GoalSubtracting a mixed number from a whole number: borrow one unit and write it as a fraction.
New words
whole number · butun sonunit · birlikmixed number · aralash kasrdifference · ayirma
Explanation
If we subtract a mixed number from a whole number, we take 1 whole from the whole number and change it into shares of the right size. For example 6 − 2 3/5: 6 = 5 5/5, so 5 5/5 − 2 3/5 = 3 2/5. Another way: subtract the whole part first (6 − 2 = 4), then the fraction (4 − 3/5 = 3 2/5).
Worked examples
5 − 2 3/8: 5 = 4 8/8, 4 8/8 − 2 3/8 = 2 5/8.
3 − 5/9: 3 = 2 9/9, 2 9/9 − 5/9 = 2 4/9.
Class activity
“Borrow a unit”: children cut one whole paper circle into quarters or eighths to show how to subtract a mixed number from a whole number.
Practice
1
Work out 5 − 2 3/8.
2 5/8
2
Work out 9 − 4 1/6.
4 5/6
3
Work out 3 − 5/9.
2 4/9
4
A store had 10 sacks of flour and 3 2/5 sacks were sold. How many sacks are left?
6 3/5
5
Solve the equation: x + 2 3/7 = 6.
3 4/7