82
Finding the whole (practice)
Textbook Part 3, pp. 18–19
GoalFinding-the-whole problems; making 10; different ways of counting.
New words
hospital · kasalxonapatient · bemorreverse order · teskari tartib
Explanation
“Some are ..., the rest are .... How many in all?” — this is a finding-the-whole problem, so we add. For quick sums, remember the pairs that make 10: 3 and 7, 4 and 6.
Worked examples
On the hospital’s 2nd floor, 7 patients got their medicine and a robot takes it to the other 4: 7 + 4 = 11 patients.
The neighbours of 99: 98 and 100.
Class activity
“Counting jumps”: the class counts together in twos from 2 to 20, in fives from 5 to 30, in tens from 10 to 100, and back from 15 to 5.
Practice
1
Make 10: 6 + _ , 3 + _ , 8 + _
4, 7, 2
2
One group has 26 children, another 31. Total?
57
3
Count backwards from 15 to 5.
15, 14, 13, 12, 11, 10, 9, 8, 7, 6, 5
4
Follow the arrows: 30 → +20 → ? → −10 → ?
50, 40