Download Mental Math

Mental Math
Why?
* Provides mental practice with basic number facts & combining operations
* Reinforces number sense:
properties of number system
measurement concepts
reasonableness of answer
math vocabulary
When?
Immediately after Math Review or during a transition time
Themes:
Patterns that exist within the number system that will deepen students’
conceptual understanding
Both problems should have the same theme.
Keep the same theme throughout the two-week Math Review cycle.
Sample Themes:
Add/Subtract 1 or 2, Make 10, Fractional Parts of Numbers, Skip
Counting, Measurement Conversions, Doubles, Multiples of 10
Procedure:
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Teacher dictates string of numbers and operations based on one or more specific
themes (kindergarten & 1st grade use a number sense based contextual problem),
pausing after each operational step for students to mentally compute. Students
should NOT write down problems/answers along the way.
Students may write the answer if they know it.
Repeat the sequence and all students should write their answers.
Group share out of answer. Choices: students chorally give answer or teacher gives
multiple choices – “Who has 15? Who has 50” Who has 100?”
Teacher states correct answer.
Process answer. Teacher chooses a student to explain thought process step by
step (teacher gives first step of problem – student explains how they thought
through that step, teacher gives next step of problem – student explains that step,
repeat for remaining steps). Teacher may choose another student to repeat this
process.
After processing the first problem, repeat the steps with another problem.
2-3 mental math problems should be done daily.
Mental Math Overview TD#3 7/16/15 Sample Mental Math Problems
* More sample mental math themes and problems are provided on EPIC.
Kinder & 1st Grade (Contextual Problems) (Kindergarten uses contextual problems all
year. 1st grade begins with contextual and transitions to number operations.)
Yesterday, I went to the park. I saw 3 big dogs and 1 little dog. How many dogs were at
the park?
Kathy has 2 Barbie dolls. Her grandma came to visit and gave her 1 Barbie doll. How
many Barbie dolls does Kathy have now?
Jose has some cars on a shelf. 3 are blue and 2 are red. How many cars on the shelf?
Shane’s mom gave him 3 cookies for an afternoon snack. He ate one cookie. How many
cookies are left to eat?
Maria saw 4 birds sitting on the grass. 2 birds flew away? How many birds are still sitting
on the grass?
Nathan got $10 from his grandparents for his birthday. He spent some money on a game
and now he has $3. How much did the game cost?
1st Grade (1st grade should begin with contextual and transition to number operations.)
(counting by 2s) Start with 10 + 2 (12); add 2 (14); add 2 (16); equals ___.”
(part-part-whole, doubles) “Start with 3 + 2 (5); subtract 3 (2); double the answer (4);
equals ___.”
(measurement, general knowledge) “Start with the number of days in a week (7); add the
number of months in a year (19); add one more (20); equals ___.”
2nd grade
(doubles, combinations that make 10) “Start with 7 + 5 (12); double the sum (24); add 6
(30); double that answer (60); equals ___.”
(part-part-whole with the quantity of 14) “Start with 6 + 8 (14); subtract 7 (7); double the
answer (14); subtract 8 (6); double the answer (12); add 2 (14); equals ___.”
(measurement, doubling) “Start with the number of inches in a foot (12); subtract 6 (6);
double the answer (12); double the answer again (24); subtract the number of inches in 2
feet (0); equals ___.”
Mental Math Overview TD#3 7/16/15 3rd grade
(counting by a given number, doubles) “Start with 3 + 3 (6);add 3 more (9); add 3 more
again (12); subtract 3 (9); double the answer (18); equals ___.”
(multiples of 5, basic facts) “Start with 2 x 5 (10); multiply by 2 (20); divide by 4 (5); multiply
by 3 (15); add 5 (20); equals ___.”
(measurement, basic facts) “Start with the number of centimeters in a meter (100); divide
by 2 (50); divide by 10 (5); multiply by the number of days in a week (35); equals ___.”
4th grade
(inverse operations) “Start with 5 x 6 (30); divide by 5 (6); multiply by 7 (42); divide by 6
(7); double the answer (14); equals ___.”
(fractions) “Start with ¼ + ¼ (1/2); add ½ (4/4, 2/2, 0r 1 whole); subtract ¾ (1/4); equals
___.”
(geometry vocabulary) “Start with the number of sides on a rectangle (4); multiply by the
number of sides on a triangle (12); multiply by 10 (120); subtract the number of degrees in
a right angle (30); equals ___.”
5th grade
(fractions of a whole) “Start with ¼ of 12 (3); double the number (6); ½ of that answer (3);
multiply by 10 (30); equals ___.”
(multiplication, powers of 10, square numbers) “Start with 7 x 8 (56); add 4 (60); multiply by
10 (600); divide by 100 (6); square the answer (36); equals ___.”
(measurement conversion) “Start with the number of inches in one yard (36); divide by 4
(9); multiply by the number of inches in one foot (108); subtract 8 (100); divide by the
number of centimeters in a meter (1); equals ___.”
6th grade
(percents, fractions) “Start with 30% of 100 (30); take half of that number (15); take a third
of that number (5); equals ___.”
(exponents, multiplication, subtraction) “Start with 33 (27); multiply by 102 (2,700);
subtract 1 (2,699); equals ___.”
(measurement conversion, division, multiplication) “Start with the number of centimeters in
a meter (100); divide by the product of 2 and 5 (10); multiply by the number of faces on a
rectangular prism (60); equals ___.”
Mental Math Overview TD#3 7/16/15 7th grade
(integers) “Start with the sum of -5 and +3 (-2); cube it (-8); subtract -2 (-6); equals ___.”
(fractions) “Start with 2/3 of 60 (40); divide by 100 (4/10); add 1/10 (5/10 or ½); equals
___.”
(probability, multiplying fractions) “Start with the probability of rolling a 3 on a die (1/6);
multiply by the probability of rolling an even number on a die (1/12); equals ___.”
8th grade
(geometry) “Start with a 56 degree angle. Determine the supplementary angle (124
degrees); divide by 4 (31 degrees); equals ___.”
(exponents, fractions) “Start with the cube root of 27 (3); divide by 6 (1/2); square it (1/4);
equals ___.”
(linear equations, integers, absolute value) “Start with the slope of y = -3x+2 (-3); multiply
by -12 (36); take the absolute value (36); equals ___.”
Mental Math Overview TD#3 7/16/15