Number Bonds
Look at this problem to help you fill in the circles of your number bond. If 40 is the big number in the number bond, what are the other two numbers in the circles.
88 - 39 = ?
88 - 40 = ______
40 = 39 + 1
45 + 23 = ?
68
87 - 34 = ?
53
Round to the nearest hundred: 482
500
Name the leading digit in the number: 8,021
8
72- 44 = ?
72- 50 = ______
50 = 44 + 6
35 + 57 = ?
92
79 - 45 = ?
34
Round each number to the nearest hundred. Give the estimated answer for the problem.
325 + 450 = ?
300 + 500 = 800
Name the leading digit in the number 712.
7
Look at this problem to help you fill in the circles of your number bond. If 40 is the big number in the number bond, what are the other two numbers in the circles.
46 + 34 = ?
46 + 40 = _____
40 = 34 + 6
25 + 42 = ?
67
72 - 47 = ?
25
Round each number to the nearest hundred. Give the estimated answer for the problem.
3,209 + 101 = ?
3,200 + 100 = 3,300
Find the answer. Then, use front end estimation with the following numbers to solve the problem.
472 + 394 = _____
____ + ____ = _____
The estimated difference is _______. Is your answer reasonable?
472 + 394 = 866
400 + 300 = 700
Yes, the answer is reasonable.
Look at this problem to help you fill in the circles of your number bond. If 57 is the big number in the number bond, what are the other two numbers in the circles.
89 - 57 = ?
89 - 50 = ______
89 - 57 = ?
89 - 50 = ____
57 = 50 + 7
281 + 532 = ?
813
426 - 296 = ?
130
Round each number to the nearest hundred. Give the estimated answer for the problem.
5,050 + 245 = ?
5,100 + 200 = 5,300
Find the answer. Then, use front end estimation with the following numbers to solve the problem.
726 - 654 = _____
____ - ____ = _____
The estimated difference is _______. Is your answer reasonable?
726 - 654 = 72
700 - 600 = 100
The estimated difference is 100. Is your answer reasonable? Yes, 72 is close to 100.
Look at this problem to help you fill in the circles of your number bond. If 100 is the big number in the number bond, what are the other two numbers in the circles.
75 + 98 = ?
75 + 100 = ____
100 = 98 + 2
434 + 512 = ?
946
852 - 463 = ?
389
Tiffinie has 231 pennies in her piggy bank.
About how many pennies do they have in all?
Round to the nearest hundred.
178 rounds to 200.
231 rounds to 200.
200 + 200 = 400.
They have about 400 pennies in all.
Solve. Use front-end estimation to estimate.
Caroline has $150. She needs $413 more to buy a vintage Nintendo 64 set. Estimate the cost of the Nintendo set.
The leading digit in $150 is 1, so the # becomes 100.
The leading digit in $413 is 4, so the # becomes 400.
$400 - $100 = $300