Estimating
Just for Fun
What's My Rule?
Multi-digit multiply
add or subtract this
100
Give an estimate for this problem: 234 + 6,789 =
200 + 7,000 = 7,200
100
What time is it when an elephant sits on the bed?
Time to get a new bed.
100
3 becomes 9 5 becomes 11 12 becomes 18
The rule is add 6.
100
45 x 2 =
90
100
7.8 + 3.2 =
11
200
Give an estimate: 4,356 + 7,349 + 2,754 =
4,000+7,000+3,000=14,000
200
Why did the cook cover the potatoes before she wrote down her secret recipe?
Because potatoes have eyes.
200
6 becomes 24 2 becomes 8 7 becomes 28
The rule is multiply by 4
200
37 x 10 =
370
200
12.3 - 5.2 =
7.1
300
Give an estimate: 34,576 + 12,987 + 9,721 =
35,000+13,000+10,000=58,000
300
Where does Santa look for new jokes?
At HO HO HO.com
300
3 becomes 90 5 becomes 150 15 becomes 450
The rule is multiply by 30
300
23 x 12 =
276
300
14.12 + 7.6 =
21.72
400
Estimate: 72,345 - 23,401 =
72,000 - 23,000=49,000
400
Are you a boy or a girl?
yes
400
42 becomes 6 21 becomes 3 777 becomes 111
The rule is divide by 7.
400
67 x 98 =
6,566
400
11.78 - 9.8 =
1.98
500
Estimate: 6,578,982 - 3,678,823 =
7,000,000 - 4,000,000 = 3,000,000
500
How do you say hello in Spanish?
hello in Spanish
500
3,972 becomes 1,324 225 becomes 75 177 becomes 59
The rule is divide by 3.
500
789 x 21 =
16,569
500
26.3 - 15.01 =
11.29
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