48
Naming and writing three-digit numbers
Textbook: Part 2, lesson 46, pp. 12–13
GoalFind the number of full hundreds and tens in a number; count in order.
New words
full hundred · to‘liq yuzlikfull ten · to‘liq o‘nlikin order, one after another · ketma-ketperimeter · perimetr
Explanation
857 has 8 full hundreds. To find the full tens, cover the last digit: 85 is left – so there are 85 full tens. When counting, 200 comes after 199 and 300 comes after 299.
Worked examples
390 has 3 hundreds and 39 tens.
198, 199, 200, 201 – the hundreds digit changes.
Class activity
“Counting train”: children stand in a line and say the next number in turn starting from 295; everyone claps when the train passes 300.
Practice
1
How many full tens are in 857?
85
2
How many full hundreds are in 286?
2
3
Count from 297 to 303.
297, 298, 299, 300, 301, 302, 303
4
A rectangle is 8 cm long and 3 cm wide. What is its perimeter in cm?
22