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Compatible Numbers . We go together!!!. By Mrs. Farrow 4C. Compatible numbers go together!. Compatible 54 and 9 16 and 4 32 and 8 12 and 3 54 and 6 18 and 2. Not compatible 17 and 2 35 and 9 15 and 4 27 and 8 24 and 5 15 and 6.
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Compatible Numbers We go together!!! By Mrs. Farrow 4C
Compatible numbers go together! • Compatible • 54 and 9 • 16 and 4 • 32 and 8 • 12 and 3 • 54 and 6 • 18 and 2 • Not compatible • 17 and 2 • 35 and 9 • 15 and 4 • 27 and 8 • 24 and 5 • 15 and 6
ESTIMATING Using Compatible Numbers • Overbidding 52 ÷ 6 overbid 52 count up: 53 no 54 yes 32 ÷ 5 overbid 32 count up: 33 no 34 no 35 yes 7 ÷ 4 overbid 7 count up: 8 yes Of course, you can use the multiples of the factor … multiplication facts.
ESTIMATING Using Compatible Numbers • Underbidding 52 ÷ 6 underbid 52 count down: 51 no 50 no 49 no 48 yes 32 ÷ 5 underbid 32 count down: 31 no 30 yes 7 ÷ 4 underbid 7 count down: 6 no 5 no 4 yes Of course, you can use the multiples of the factor … multiplication facts.
Compatible Numbers Underbidding Overbidding 20 17 ÷ 5 4 36 29 ÷ 9 4 48 42 ÷ 8 6 • 17 ÷ 5 3 15 • 29 ÷ 9 3 27 • 42 ÷ 8 5 40
Patterns Using zeroes • ÷ 6 = 9 540 ÷ 6 = 90 5,400 ÷ 6 = 900 54,000 ÷ 6 = 9,000 54 divided by 6 is 9. Count your zeroes. Write your zeroes. Add comma if needed! 54 is compatible with 6.
ESTIMATE • Use compatible numbers (underbid and overbid) • Use patterns (you need zeroes) 16 2 • 14 ÷ 8 8 1 160 20 • 146 ÷ 8 80 10
Notes to help you! 180 • 158 ÷ 6 120 • Overbid 15 • Change 8 to 0 • Underbid 15 • Change 8 to 0 • Estimate using patterns
TRY THESE Use paper and pencil. Check on next page. • 73 ÷ 2 • 139 ÷ 2 • 236 ÷ 7 • 653 ÷ 9 Estimate • Did you overbid? • Did you underbid? • Did you change numbers to zero?
Check your work! 80 40 140 70 73 ÷ 2 139 ÷ 2 60 30 120 60 280 40 720 80 236 ÷ 7 653 ÷ 9 210 30 630 70
OK! NOW TRY THESE Turn in your paper for the teacher to check! Remember to add zeroes to use patterning. • ÷ 3 6,771 ÷ 8 643 ÷ 4 3,957 ÷ 5 608 ÷ 5 4,759 ÷ 9 709 ÷ 2 455 ÷ 7