Mental Math
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Tell me a number…one less
One more
Half of the number
Double the number
Double plus one
Double minus one
Roll the dice on the SmartBoard
If this is the answer, what is the question?
Ten More/Ten Less
Today’s Number is…
Select a number for the day (e.g. 8) and write it on the board or chart paper. Ask students to
suggest calculations for which the number is the answer. Write students' suggestions in 4
columns (addition examples, subtraction, multiplication and division). After 8 or 10 responses,
focus in on particular columns or types of responses that you would like more of. For example,
"Give me some more addition examples", "Give me some ways which use three numbers", "Give
me an example using parentheses" etc.
What's My Number
Select a number between 1 and 100 and write it down without revealing it to your students.
Have students take turns to ask questions to which you can only answer ‘yes’ or ‘no’. Record
each question and answer on chart paper. For example:
Is it greater than 30? No
Is it an even number? Yes
Is it a multiple of 3? No
Does it have a 4 in the ones place?...
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After 3 or 4 questions ask, “What is the smallest number it could still be? What is the largest?
Discuss why it is better to ask a question such as "Is it an odd number?" than "Is it 34?" early in
the game. To ensure that all students are involved have them use individual laminated 100
charts with dry erase markers to mark off numbers after each question is asked. Keep going until
the number has been named correctly. During the game you may also want to keep track of how
many questions are asked before the number is named. Next time you play challenge students
to guess the number with fewer questions.
'Friendly' number activities
Give a number less than 10. Students must respond with an addition fact that will make the
number up to 10. For example, if today's target number is 10 and you say 6 the student must
respond with "6 + 4 = 10". Vary the target number e.g. 20, 50, 100, 200, 1000 etc. to suit
students' ability level.