Rounding rules
What digit tells you whether to round up or down?
The digit to the right of the place value you are rounding
Round 792 to the nearest ten
790
Estimate: 328 + 239 by rounding to the nearest ten
330+240=570
Solve: 328+239
567
What unit is used to measure weight: grams or liters
grams
The ones digit
Round 792 to the nearest hundred
800
Estimate: 537-489 by rounding to the nearest ten
540-490=50
Solve: 428-169
259
What unit is used to measure liquid capacity?
Liters
When rounding to the nearest hundred, which digit do you look at?
The tens digit
Round 849 to the nearest ten
850
Estimate: 537-489 by rounding to the nearest hundred
500-500=0
Solve: 600-176
424
A notebook weighs about 30g or 300g?
300 grams
If the digit you look at is 5 or greater, what do you do?
Round up
Round 849 to the nearest hundred
800
Estimate: 456+302 rounding to the nearest hundred
500+300=800
Solve: 492+158
650
A kitchen sink holds about 40L or 400L of water?
40 liters
True or False: When rounding 349 to the nearest hundred, you look at the 4 to tell you if you round up or down.
True
Round 495 to the nearest hundred
500
Pablo wants to estimate 537 − 489.
Should Pablo round both numbers to the nearest ten or to the nearest hundred? Explain your thinking.
To the nearest ten because it will give a more accurate estimate of the actual difference.
A shark weighs 286 kilograms more than an octopus. The shark weighs 315 kilograms.
How much does the octopus weigh?
29
A student desk weights about 12kg or 120kg?
12kg