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E:\Working\Focus_Learning\Math_Genius_3_(11-09-2024)\Open_Files\CHAP_02
\ 12-Sep-2024 Surender Prajapati Proof-4 Reader’s Sign _______________________ Date __________
(c) 3256 + 4098 (d) 5981 + 3527
th H t O th H t O th H t O th H t O
+ + + +
maths fun
Add the following and search the answers in the clue box. Now, fill the
corresponding alphabets in the boxes given below to decode the secret message.
(a) 2875 + 10 = ____ (b) 4438 + 10 = ____ Clue Box
(c) 7547 + 100 = ____ (d) 6399 + 10 = ____ T 9913 7647 A
(e) 8930 + 100 = ____ (f) 8913 + 1000 = ____ 6409 E 6474 V
(g) 9398 + 100 = ____ (h) 7843 + 1000 = ____ 2885 M H 8843
(i) 4538 + 1000 = ____ (j) 6464 + 10 = ____ L 5538 9498 S
Secret message: O 4448 9030 I
(e) (i) (b) (j) (d) (a) (c) (f) (h) (g)
estimAting the sum
Siya: Yesterday, the Hockey World Cup match was so exciting.
rahul: Do you know there were 6052 men, 2456 women and 1201 children who were
spectators of this interesting match?
Siya: Wow! It means the total number of tickets sold was around 10000.
rahul: Yes.
Let us see how Siya calculated the total sum around 10000.
Estimating the sum is a rough calculation done without actually adding the numbers. We
can estimate the sum by rounding off the numbers.
For example, let us find the estimated sum of 18 and 14 using the following steps:
Step 1: Since in 18, the ones digit is 8, which is greater than 5 (8 > 5).
So, 18 is rounded up to 20.
Step 2: In 14, the ones digit is 4, which is less than 5 (4 < 5). t O t O
So,14 is rounded down to 10. 1
Step 3: Now, add 20 and 10. 1 8 round up 2 0
Thus, the estimated sum of 18 and 14 is 30. + 1 4 round down + 1 0
While the actual sum is 32. 3 2 3 0
Mathematics-3 43

