☰ Contents · Mathematics

Brackets and adding across ten

Lessons 50–53 · 4 lessons · I.V. Repyova, Y.V. Zemlina. Mathematics Grade 1, Parts 1–4. Novda Edutainment, 2023
52

Adding across ten

Textbook Part 2, pp. 24–25
GoalAdd one-digit numbers by making ten first (8 + 5 = 8 + 2 + 3).
New words
a full ten · to‘liq o‘nlikmaking ten · 10 gacha to‘ldirishsplitting · bo‘laklash
Explanation

When a sum goes past 10, first make the first number up to 10, then add the rest. 8 + 5: 8 needs 2 to make 10. Split 5 into 2 and 3: 8 + 2 = 10, 10 + 3 = 13.

Worked examples
8 pupils stand by the bus; 5 more people arrive: 8 + 5 = 8 + 2 + 3 = 13.
9 + 4 = 9 + 1 + 3 = 13
Class activity

“Ten frame”: put 8 counters in a 2×5 frame, then add 5 more — first fill the frame (2), and the other 3 go outside.

Practice
1
9 + 5 = ?
2
8 + 6 = ?
3
7 + 5 = ?
4
A bag can carry 11 kg. The items weigh 4 kg, 3 kg and 5 kg. Can it carry them all?