52
Adding three-digit numbers
Textbook: Part 2, lesson 50, pp. 20–21
GoalAdd three-digit numbers place by place (no regrouping).
New words
addend · qo‘shiluvchisum · yig‘indicolumn · ustunplace · xona
Explanation
We add three-digit numbers place by place: ones to ones, tens to tens, hundreds to hundreds. 425 + 534: 5 + 4 = 9 ones, 2 + 3 = 5 tens, 4 + 5 = 9 hundreds – the answer is 959. In a column the digits are written one under another.
Worked examples
108 + 371: 8 + 1 = 9, 0 + 7 = 7, 1 + 3 = 4. The answer is 479.
836 + 62 = 898: the hundreds stay the same because 62 has no hundreds.
Class activity
“Magic column”: write a column sum on the board. Children take turns solving one place at a time – ones, then tens, then hundreds – and the class reads the answer together.
Practice
1
108 + 371 = ?
479
2
425 + 534 = ?
959
3
836 + 62 = ?
898
4
For school repairs 564 bricks came in the morning and 225 in the evening. How many bricks in total?
789