Rounding Numbers

1. Rounding Numbers 660 630 600 700 74 77 70 80

2. Today we will round numbers 6.C.2.aDetermine the reasonableness of sums and differences Maryland Student Technology Standard: 3.A.1.a Explore and use teacher-selected technology tools, including software and hardware, to learn content or reinforce skills.

3. The Rule • Look at the number to the right of the rounding number. If that number is 0, 1, 2, 3, or 4, do not change the rounding number. All the numbers on the right side of the rounding number will become 0.

4. Round 64 to the nearest 10. Look at the number to the right of the tens place. Since the number is 4, leave the 6 as it is and change the 4 to 0. 60

5. The Rule • If the number to the right of the rounding number is 5, 6, 7, 8, or 9, the rounding number rounds up one number. All the numbers to the right of the rounding number become 0.

6. Round 270 to the nearest 100. Look at the number to the right of the hundreds place. Since the number is 7, round up the 2 and make it 3. Then make the other two numbers 0. 300

7. Rounding to the Nearest 10 65 64 66 63 67 62 68 61 69 70 60

8. Rounding to the Nearest 100 350 340 360 330 370 320 380 310 390 400 300

9. Now it’s your turn!

10. 10 Round 37 to the nearest 10. • 30 • 40 • 35 • 25

11. 10 Round 23 to the nearest 10. • 20 • 25 • 30 • 35

12. 10 Round 670 to the nearest 100. • 500 • 600 • 650 • 700

13. 10 Round 734 to the nearest 100. • 600 • 750 • 800 • 700

14. 10 28 students are in Mrs. Smith’s class. About how many students are in her class? • 20 • 30 • 40 • 50

15. 10 There are 132 pencils in the box. About how many pencils are in the box? • 100 • 200 • 300 • 50