Learning to estimate requires opportunities for trial and error. Create an estimation station in the classroom where individuals or small groups of students can practice estimating groups of various-sized items. Stock the area with piles of objects such as buttons, marbles, plastic cubes, paper clips, cotton balls and pieces of ribbon and yarn. Teach students how to grab a pile of like objects, write down a guess as to how many there are in the group and then count to check for accuracy. Encourage the students to think about their estimations by asking questions like, "Was my estimate too large? Too small? Close to the actual number?"
Working with nontraditional units of measurement gets students thinking about the size of objects in relation to each other, giving kids valuable insight into the concept of measurement. Give each student a pile of paper clips and ask them to measure a book, a desk, their shoes or their friend's arm to determine the length in paper clips. Teach students to record an estimate first, followed by the actual measurement. Later, have students analyze the measurements to determine if their estimations were close to the actual measurements. Other nontraditional units include wooden craft sticks, cotton balls and edible treats like gummy candies or O-shaped cereal.
Dice addition and subtraction lets first-graders practice adding or subtracting two or more numbers. The game is simple to play for one or more players. Required materials include two or more dice and a scrap piece of paper or an erasable board for each player. Players take turns rolling the dice, adding or subtracting the numbers and recording the sum or difference. The player with the higher sum or difference after each roll wins that round. At the end of the game, players can use a calculator to add the entire column of sums or differences to determine a grand total.
Card games provide an engaging way to practice computation skills. "Elevens" is a one-player game where a student turns over nine cards at a time and tries to find groups of cards that add up to 11. Change the sum to any number for additional practice. Students can also play "Seventeen" with a partner. Separate the deck so you have only aces and number cards 1 through 8. Each player gets five cards. The first player plays any card; the next player adds the card she plays to the first card played. The object is to get as close as possible to 17 without going over. The next hand begins after the winner gets as close as possible to 17 and no one else can play a card.