Solve the following problems: a) Round 138 to the nearest tens. b) Round 4998 to the nearest thousands. c) Round 4382 to the nearest hundreds. d) Round 482602 to the nearest thousands. e) Round 998 to

a) Round 138 to the nearest tens. The tens digit is 3. The digit to its right is 8. Since $8 \ge 5$, we round up the tens digit.

b) Round 4998 to the nearest thousands. The thousands digit is 4. The digit to its right is 9. Since $9 \ge 5$, we round up the thousands digit.

c) Round 4382 to the nearest hundreds. The hundreds digit is 3. The digit to its right is 8. Since $8 \ge 5$, we round up the hundreds digit.

d) Round 482602 to the nearest thousands. The thousands digit is 2. The digit to its right is 6. Since $6 \ge 5$, we round up the thousands digit.

e) Round 998 to the nearest tens. The tens digit is 9. The digit to its right is 8. Since $8 \ge 5$, we round up the tens digit. This causes a carry-over to the hundreds place.

f) Round 4769 to the nearest hundreds. The hundreds digit is 7. The digit to its right is 6. Since $6 \ge 5$, we round up the hundreds digit.

a) Add 473442 and 369270.

b) Subtract 7824 from 72608.