# Explorations In Math

## Simple Games to Practice Number Fluency

These activities have been used by our Mathematicians in Residence in classrooms and clubs to help students increase number understanding and fluency. Fluency then builds self-esteem.  Try them out when you have some free time waiting in a restaurant or for extra homework practice.

## Primary (K-2) Skill Building Activities

NEW! Mental Math with Playing Cards (Number Sense):

Predetermine the “rule” of the game, such as “Add 5″ or “Double it”.  Prepare a deck of cards by removing all the face cards and jokers.  Then have the child turn over one card at a time and apply the “rule” then give the answer.  For example, the child turns over an 8, they add 5 mentally and give the answer of  13.  Help them identify different strategies (counters, fingers, etc.) for coming to the correct answer.

Find Ten (STRAND: Number Sense-Addition: Finding Tens):

A math game similar to Concentration. In this game, children try to make a ten by turning over combinations of cards that total ten. You’ll need a deck of cards with face cards and tens removed (1-9, aces = 1). Mix up the cards and place six rows of six cards face down between two players. (Three can also play or four in teams of two.) Taking turns, players turn over two cards. If the sum is ten, the player takes the cards and plays again. If the sum is greater than ten, the cards are replaced face down and that player’s turn is over. The game is over when no more tens can be made. The player with the most combinations of ten wins.

VARIATION: Use Jokers or face cards as wild cards.

Fingers (STRAND: Number Sense-Computational Fluency):

Students can compete in groups of 2 for multiplication or subtraction.  Larger groups are acceptable for addition.  To practice with addition, 2 students face each other with one hand behind their back, extending anything from 1-5 fingers.  They reveal the number of fingers (show their hand) at a signal.  The first to state the sum of the two hands wins that round.

For subtraction two players can extend any number of fingers on one or two hands. The first to state the difference wins the round.

For multiplication two players can extend any number of fingers on one or two hands. The first to state the product wins the round.

What’s My Number? (STRAND: Mathematical Reasoning):

This game is about students learning to be systematic, methodical and organized in their reasoning.  Tell the students you’re thinking of a number between 1-100. Their task is to determine what your number is using no more than 7 “yes or no” questions. As soon as a student asks, “Is it ___?”, the game is over, right or wrong.  Students should soon realize that questions that eliminate half of the options (ex. “Is it >50?” or  “Is it an even number?”) will get them to the mystery number faster.

## Intermediate (gr. 3-5) Skill Building Activities

NEW! Mental Math (Number Sense):

This activity helps children get comfortable with mental calculating and can be done anywhere you are.  Tailor the level of difficulty to the ability of the child(ren) playing.  For older children, you might say, “Start with 5;  Double that;  Add 7;  Subtract 9;  Times 3;  Divided by 6.  What’s the answer?”.   Over time, you can increase the speed and complexity, sometimes adding fractions or factorials.  For younger children, use only addition and subtraction.

Subtraction Pole Vault (STRAND: Number Sense):

This game can be played solo or with 2 or more players. You’ll need a calculator (to verify answers), paper and a deck of cards with 10s, Jacks, Kings removed. Ace = 1, Queen = 0. The object is to get as close to 0 as possible, without going below 0, after five subtractions from a target number.

Shuffle the cards, place deck face down. The target number is 250 (or whatever the teacher or players decide on). Players take turns doing the following:

• Player 1 turns over top two cards and makes a two-digit number. Subtract this number from 250 on scratch paper, check on calculator. Player 2 then does the   same.

• Turn over the  next two cards, make a two-digit number and subtract from the result in step one.

•Do this three more times.

• Whoever is closest to 0 (without going over) after five rounds, wins.

EXAMPLE:

Turn 1: Draw 4 & 5 ,      Subtract either 45 or 54 ,        250 – 45 = 205

Turn 2: Draw 0 & 6,          Subtract either 6 or 60,           250 – 60 = 145

And so on.