26
Adding (28 + 14)
Textbook: Part 1, lesson 25, pp. 54–55
GoalLearn adding two-digit numbers with carrying (28 + 14).
New words
tens · o‘nliklarones · birliklargadget · gadjettablet · planshet
Explanation
When adding two-digit numbers we add tens to tens and ones to ones. 28 + 14 = (20 + 10) + (8 + 4) = 30 + 12 = 42. If the ones add up to more than 10, the ten in them joins the tens.
Worked examples
34 + 58 = (30 + 50) + (4 + 8) = 80 + 12 = 92.
29 + 25 = (20 + 20) + (9 + 5) = 40 + 14 = 54.
Class activity
“Big tens”: the teacher says two numbers (37 and 24). Children add the tens first, then the ones, and write the sum on the board.
Practice
1
37 + 24 = ?
61
2
48 + 15 = ?
63
3
67 + 25 = ?
92
4
A library has 15 computers, 16 tablets and 5 microphones. How many in all?
36