STAAR Grade 5 Math

An estimate is a close answer that is easy to find with mental math. Estimating helps you check whether an exact answer makes sense, and some STAAR questions ask only for an estimate.

To estimate a product, round each factor to a number that is easy to multiply. To estimate a quotient, use compatible numbers: numbers that are close to the real numbers and divide evenly.

To multiply a 3-digit number by a 2-digit number, you can break each factor into its place values. Multiply every part by every part. Each answer is a partial product. Add the partial products to get the final product.

The standard algorithm is a shorter way to record the same partial products. You multiply by the ones digit, then by the tens digit, and add the two rows.

In a division problem, the dividend is the number being divided, the divisor is the number you divide by, and the quotient is the answer. Grade 5 problems use dividends up to four digits and divisors with two digits.

One strategy is partial quotients. Take away easy multiples of the divisor, such as 100, 10, or 5 groups, until nothing is left. Then add the partial quotients.

You can also use the standard algorithm: divide, multiply, subtract, bring down, and repeat. Estimating each digit with compatible numbers helps. For example, to start 3,276 ÷ 28, think "about how many 28s are in 32?" The answer is 1.

When a divisor does not go in evenly, the leftover amount is the remainder. In a word problem, you must decide what the remainder means. Read the question to see what it asks for.

Multiplication and division are inverse operations. They undo each other. To check a quotient, multiply it by the divisor and add any remainder. You should get the dividend.