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How many more? (practice)
Textbook Part 3, pp. 40–41
GoalSolve age-difference and other comparison problems; make a problem from a short note.
New words
cosmonaut · kosmonavthow many years older · necha yosh kattaequality · tenglik
Explanation
To find an age difference, subtract the younger age from the older. This difference never changes over the years. Any “who has more and by how much?” problem takes two steps: 1) which is more; 2) larger − smaller.
Worked examples
Yuri Gagarin flew into space at 27. Uzbek-born Vladimir Dzhanibekov was 36 on his first flight: 36 − 27 = 9 years older.
How much smaller is 76 than 88? 88 − 76 = 12.
Class activity
“Space table”: children pick two facts from a table on the board, make up a “who is older and by how much” question and pass it on.
Practice
1
Find the sum of 26 and 13.
39
2
Find the difference of 77 and 12.
65
3
Short note: Father — 38, Son — 7. Difference?
31
4
Colour stars so yellow > red > blue > green (10 in all). How many of each could there be?
For example: 4, 3, 2, 1