1. **Complete the table by rounding each number:** - For 3.78: - Nearest tenth: Look at the hundredths place (8), which is 5 or more, so round up the tenths place from 7 to 8. - Result: 3.8 - Nearest whole number: Look at the tenths place (7), which is 5 or more, so round up the units place from 3 to 4. - Result: 4 - For 4.45: - Nearest tenth: Hundredths place is 5, so round up tenths from 4 to 5. - Result: 4.5 - Nearest whole number: Tenths place is 4, less than 5, so keep units place 4. - Result: 4 - For 3.55: - Nearest tenth: Hundredths place is 5, round up tenths from 5 to 6. - Result: 3.6 - Nearest whole number: Tenths place is 5, round up units from 3 to 4. - Result: 4 - For 4.04: - Nearest tenth: Hundredths place is 4, less than 5, keep tenths 0. - Result: 4.0 - Nearest whole number: Tenths place is 0, less than 5, keep units 4. - Result: 4 2. **Which numbers round to 9.45 when rounded to the nearest hundredth?** - Rounding to the nearest hundredth means looking at the thousandths place. - Check each number: - 9.356: Thousandths = 6, so hundredths 5 rounds up to 6 → 9.36 (No) - 9.425: Thousandths = 5, hundredths 2 rounds up to 3 → 9.43 (No) - 9.455: Thousandths = 5, hundredths 5 rounds up to 6 → 9.46 (No) - 9.453: Thousandths = 3, less than 5, hundredths stays 5 → 9.45 (Yes) - 9.459: Thousandths = 9, rounds hundredths 5 up to 6 → 9.46 (No) - 9.448: Thousandths = 8, rounds hundredths 4 up to 5 → 9.45 (Yes) **Correct answers:** 9.453 and 9.448 3. **Use digits 9, 4, 1, 2 once to make the decimal number closest to 20:** - To get close to 20, the number should be near 20.00. - The digits can be arranged as a two-digit number plus decimal digits. - Try 19.42, 19.24, 21.49, 21.94, etc. - 21.94 is 1.94 away from 20, 19.42 is 0.58 away, 19.24 is 0.76 away. - 19.42 is closest to 20. **Answer:** 19.42 4. **Mizhir's cards problem:** - Cards: 0.45, 1.45, 2.45, 3.45 - He picks two cards, adds them, rounds to nearest whole number, result is 5. - Check all pairs: - 0.45 + 1.45 = 1.90 → rounds to 2 - 0.45 + 2.45 = 2.90 → rounds to 3 - 0.45 + 3.45 = 3.90 → rounds to 4 - 1.45 + 2.45 = 3.90 → rounds to 4 - 1.45 + 3.45 = 4.90 → rounds to 5 (correct) - 2.45 + 3.45 = 5.90 → rounds to 6 **Answer:** He chose 1.45 and 3.45 Final answers: | Number | Rounded to nearest tenth | Rounded to nearest whole number | |--------|--------------------------|---------------------------------| | 3.78 | 3.8 | 4 | | 4.45 | 4.5 | 4 | | 3.55 | 3.6 | 4 | | 4.04 | 4.0 | 4 | Numbers rounding to 9.45: 9.453, 9.448 Closest decimal to 20 using digits 9,4,1,2: 19.42 Mizhir's cards: 1.45 and 3.45