142
One thousand
Textbook: Part 4, lesson 132, pp. 36–37
GoalUnderstand one thousand as 10 hundreds; subtract from 1000 and complete to 1000.
New words
one thousand · minghundred · yuzlikten · o‘nlikcompleting · to‘ldirish
Explanation
The number after 999 is 1000 (one thousand). A thousand is 10 hundreds or 100 tens: 100 × 10 = 1000. Subtracting from 1000: 1000 − 200 = 800, 1000 − 20 = 980, 1000 − 2 = 998. If 1000 − x = 850, then x = 1000 − 850 = 150. If x + 120 = 1000, then x = 1000 − 120 = 880.
Worked examples
600 + 400 = 1000, so 1000 − 600 = 400.
1000 : 10 = 100 and 1000 : 100 = 10.
Class activity
“Reaching a thousand”: the teacher puts up 100-cards one by one. Children count “100, 200, … 900, 1000!” and answer “how many more to reach 1000?”
Practice
1
1000 − 200 = ?
800
2
1000 − 20 = ?
980
3
1000 − 2 = ?
998
4
1000 − x = 850, x = ?
150
5
x + 120 = 1000, x = ?
880
6
In all, 1000 tickets were given to two groups. The first group got 4 × 100 tickets. How many tickets did the second group get?
600