Transcript RNE Lesson 19 Luke

Estimating Products and Quotients
1.
Spot the Dog lost 1.85 pounds after his surgery. Two
weeks later he had gained back 1.2 pounds. What
number represents his total change in weight since
the surgery?
2.
Keyla ran 2 13 miles each day for 5 days. What was
the total distance she ran over these 5 days?
3.
1
( 28)
4
4.
7(6)

Compatible #’s:
◦ easy to compute in your head
Estimate using compatible numbers.
61.2 ÷ 6.94

Round the divisor

7 14 21 28 35 42 49 56 63
1 2 3 4 5 6 7 8 9



61.2 ÷ 7
Change the dividend to the nearest
multiple of the new divisor.
63 ÷ 7
Divide.
63 ÷ 7 = 9
61.2 ÷ 6.94 ≈ 9
Estimate using compatible numbers.

1
 23 72 
4
Choose a compatible number for the mixed number.
1
 24 
4

Multiply.
1
 24   6
4
1
 23 72   6
4
Estimate using compatible numbers.
–31.82 ÷ (–3.19)
11.4 ÷ (–1.78)
1
(57)
11
1
 22 34 
6
How are compatible numbers helpful when dividing two
rational numbers?