how do you round 638 to the nearest 10?
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How do you round 638 to the nearest 10?. 6 3 8. 6 4 0. 6 3 0. Midpoint. l l l l l l l l l l l. In this lesson you will learn how to round to the nearest 10 by using a number line. I I I I I I I I I. l l. - PowerPoint PPT PresentationTRANSCRIPT
How do you round 638 to the nearest 10?
l l l l l l l l l l l
630 640638
Midpoint
In this lesson you will learn how to round to the nearest 10
by using a number line.
Let’s ReviewLet’s Review
l l
150 160I I I I I I I I I
Benchmark Numbers
151 152 153 154 155 156 157 158 159
l l
100 200I I I I I I I I I
110 120 130 140 150 160 170 180 190
Let’s ReviewLet’s Review
Rounding - To find a number that is close to a given number.
l l l l l l l l l l lBakery
Morgan
Ashley Pizza
Let’s ReviewLet’s Review
I I I I I I I I Il l
400 500
Benchmark Numbers
410 420 430 440 450 460 470 480 490
What is a midpoint?
The midpoint marks the
middle of the line.
Let’s ReviewA Common Mistake
Thinking that the increments on a number line always signify counting by
ones.
l l l l l l l l l 300 400 310 320 330 340 350 360 370 380 390
Let’s ReviewA Common Mistake
Knowing when to round up or round down.
It is important to consider the number size and the benchmark numbers when
rounding.
Let’s ReviewCore Lesson How can I use benchmark numbers and midpoints to help
me round?
l l l l l l l l l l l
410 420415
Numbers less than the midpoint round down.
Numbers the same as or greater than the midpoint round up.
Let’s ReviewCore Lesson
l l l l l l l l l l l
410
420415
410 420
415410 - 414 415-420
Let’s ReviewCore Lesson
Round 72 to the nearest 10.
70 80
Midpoint
75 l
Let’s ReviewCore Lesson
Round 368 to the nearest 10.
l l l l l l l l l l l360 370361 362 363 364 365 366 367 368 369
Benchmark Numbers
Midpoint365
Let’s ReviewCore Lesson
Rounding Down:132 130
Rounding Up:135 140
Let’s try another one!
In this lesson you have learned how to round to the nearest 10
by using a number line.
Let’s ReviewGuided Practice
Round 84 to the nearest 10.
Round 748 to the nearest 10.
Let’s ReviewExtension Activities
In your math journal discuss how you know when to round up to the greater ten.
Let’s ReviewExtension Activities
Draw a number line. Find the benchmark numbers for 43. Place 43 on the number line.
Would you round up or down?
Is 43 below or above the midpoint?
Let’s ReviewExtension Activities
Write 3 numbers that would round to 130.
Include numbers that round up and round down.
Let’s ReviewQuick Quiz
1). Which of these numbers would not round to 250?
246 252 249 254 255
2). Round 477 to the nearest ten.