Download ≅ means approximately equal to

Estimating Square Roots
All numbers are not perfect squares, but they can still be square rooted!!
√15
√17
√12
We can estimate to find the square roots of non­perfect square numbers.
Think of your list of perfect squares...
4 9 16 25 36 49 64 81
1
√18
12 22 32 42 52 62 72 82 92
1
4 9 16 25 36 49 64 81
√18
Falls between 16 & 25
Always go to the closer of the two perfect squares ­ and choose 3 decimal numbers and square them
ie:
4.12 = 4.1 x 4.1 = 16.8
4.22 = 4.2 x 4.2 = 17.64
4.32 = 4.3 x 4.3 = 18.49
Choose the closest number to 18, without going over 18
∴ √18 ≅ 4.2
≅ means approximately equal to
1
√8
1
Falls between 4 & 9, but is closer to 9, so the answer is above 2.5
4 9 16 25 36 49 64 81
2.62 = 2.6 x 2.6 = 6.76
2.72 = 2.7 x 2.7 = 7.29
2.82 = 2.8 x 2.8 = 7.84
2.92 = 2.9 x 2.9 = 8.41
Try these...
1. √13
3. √27
5. √42
2.
4.
6.
∴ √8 ≅ 2.8
√24
√83
√91
Book Work...Pages 25 ­ 27
#'s 4, 5, 7, 8, 9, 10, 13, 14, 15, 16, 17, 22, 23
Work Sheets 11 & 12
2
3