(6) Write the predecessor of:
a. 94
Predecessor means deduction of 1.
94 – 1 = 93
93 (Ans)
b. 10000
Predecessor means deduction of 1.
10000 – 1 = 9999
9999 (Ans)
c. 208090
Predecessor means deduction of 1.
208090 – 1 = 208089
208089 (Ans)
d. 7654321
Predecessor means deduction of 1.
7654321 – 1 = 7654320
7654320 (Ans)
(7) In each of the following pairs of numbers, state which whole number is on the left side of the number on the number line. Also write them with the appropriate sign (>,<) between them.
a. 530, 503
Sol. The smaller number lies on left side and the bigger number lies on the right side of the number line
503 is smaller than 530
Therefore, 503 lies on left side and 530 lies on right
530 > 503
b. 370, 307
Sol. The smaller number lies on left side and the bigger number lies on the right side of the number line.
Here, 307 is smaller than 370
Therefore, 307 lies on left side and 370 lies on right
370 > 307.
c. 98765, 56789
Sol. The smaller number lies on left side and the bigger number lies on the right side of the number line.
Here, 56789 is smaller than 98765
Therefore, 56789 lies on left side and 98765 lies on right
98765 > 56789.
d. 9830415, 10023001
Sol. The smaller lies on left side and the bigger number lies on the right side of the number line.
Here, 9830415 is smaller than 10023001.
Therefore, 9830415 lies on left side and 10023001 lies on right side.
9830415 < 10023001.
(8) Which of the following statements are True (T) and which are false (F)?
a. Zero is the smallest natural number.
Ans. False
Reason – Because natural number starts with 1 and goes up to infinity.
Therefore, smallest natural number is 1.
b. 400 is the predecessor of 399.
Ans. False
Reason – Because predecessor means deducting 1 from the number. Therefore, predecessor pf 399 is 399 – 1 = 398. 400 is the successor of 399.
c. Zero is the smallest whole number.
Ans. True
Reason – Whole number starts with 0 and goes up to infinity. Therefore, the statement is correct.
d. 600 is the successor of 599.
Ans. True.
Reason – Because successor means adding 1 in the given number. Therefore, 599 + 1 = 600. Hence, the statement given is correct
e. All-natural numbers are whole numbers.
Ans. True
Reason – Whole number = All natural numbers + 0. Therefore, the statement given is correct.
f. All whole numbers are natural numbers.
Ans. False
Reason – Whole number = All natural numbers + 0. It means all whole numbers are not natural numbers and thus the statement given is correct.
g. The predecessor of a two-digit number is never a single digit number.
Ans. False
Reason – predecessor means deducting 1 from the number. 10 is a two-digit number whose predecessor is 9 which is a single digit number. Therefore, the statement given is not correct.
h. 1 is the smallest whole number.
Ans. False
Reason – Whole number starts with 0 and goes up to infinity. Therefore, smallest whole number is 0 not 1. Therefore, the statement given is not correct.
i. The natural number 1 has no predecessor.
Ans. True.
Reason – natural number starts with 1 and goes up to infinity. Therefore, natural number 1 has no predecessor. Hence, the statement is correct.
J. The whole number 1 has no predecessor.
Ans. False
Reason – Whole number starts with 0 and goes up to infinity. Therefore, whole number 1 has 0 as its predecessor. Hence, the statement is not correct.
k. The whole number 13 lies between 11 and 12.
Ans. False
Reason – 13 lies after both the whole number 11 and 12.
l. The whole number 0 has no predecessor.
Ans. True
Reason – Whole number starts with 0 and goes up to infinity. Therefore, whole number 0 has no predecessor. Hence, the given statement is correct.
m. The successor of a two-digit number is always a two-digit number.
Ans. False
Reason – successor means adding 1 in the given number. 99 is two-digit number whose successor is 99 + 1 = 100, which is three-digit number. Therefore, the given statement is not correct.