Rounding
When rounding 672 to the nearest 10, what number would be underlined?
The 7 because that number is in the tens place.
What two addends would you add together when estimating the sum of 723+141 by rounding to the nearest 100?
700+100
Does the order of addition matter? AKA, does it matter how the numbers are stacked?
No, you can add in any order.
When adding, what place value must you start in?
The ones place
True or False; When doing subtraction you start with the ones place, then the hundreds, then the tens?
When rounding 892 to the nearest hundred, what are the 2 options you have to round it to?
800 and 900
What two numbers would you subtract when estimating the difference of 345-287 by rounding to the nearest 10?
350-290
Does the order of subtraction matter? AKA does it matter how the numbers are stacked?
Yes, the larger number must be on top. AKA you have to subtract from the larger number.
How do you know you need to regroup when adding?
When you get a sum in the ones or tens place that is larger than 9.
How do you know you need to regroup when subtracting?
When you can't subtract numbers in the ones or tens place because the number on bottom is larger/number on top is smaller.
When rounding 756 to the nearest ten, what are the two options for possible answers?
750 and 760
Estimate the sum of 542+159 by rounding each addend to the nearest ten.
540+160=700
What property of addition is being show below?
52+0=52
Identity or Zero Property. This says that the sum of any number and zero is that number.
Do you have to regroup when adding 572+419
Yes, you have to regroup the ones.
Do you have to regroup when subtracting 492-321
No
Round 892 to the nearest hundred
900
Estimate the sum of 482+325 by rounding to the nearest 100.
500+300=800
What property of addition is being show below?
61+23=23+61
The commutative property of addition. This deals with order. Addends can be grouped in any order.
Add 291+627=
918
Subtract 943-261
682
Round 427 to the nearest ten
430
Estimate the difference of 723-509 by rounding to the nearest 10
720-510=210
What property of addition is being show below?
(12+20)+7=(7+20)+12
The associative property of addition. This eals with grouping. Addends can be grouped in any way and still get the same sum.
Add 192+284+357
833
Subtract 626-357
269