128
Properties of zero
Textbook: Part 4, lesson 119, pp. 8–9
GoalKnow the properties of zero: multiplying by 0 and dividing 0 by a number.
New words
zero · nolproperty · xossaquotient · bo‘linmanothing · hech narsa yo‘q
Explanation
Any number times zero gives zero: a × 0 = 0 × a = 0. Adding “seven zeros” still gives nothing. Zero divided by any number is zero again: 0 : a = 0. For example, sharing 0 apples among 3 children gives each child 0. We cannot divide by zero.
Worked examples
0 × 5 = 0 and 7 × 0 = 0.
0 : 4 = 0, because sharing 0 things among 4 gives 0 each.
Class activity
“Empty baskets”: all 3 baskets are empty. Children write the expression for “0 in each basket, how many in all of 3 baskets?”. Then they act out “sharing 0 apples among 3 children”.
Practice
1
0 × 3 = ?
0
2
7 × 0 = ?
0
3
0 : 6 = ?
0
4
(14 : 7) + (0 : 3) = ?
2
5
A reserve has 3 pens, each with 5 fawns. How many fawns are there in all?
15