PRACTICE 21 Last year you talked about fact families for addition and subtraction. Fact families showed 3 numbers in 4 problems. 2 problems were addition and 2 problems were subtraction. Example: Create fact families for the following three numbers. 4 5 9 ANSWER: Start with addition. The largest number (9) is your answer, so it stays on the right for both problems. You switch the other two numbers around to make 2 problems 4 + 5 = 9 5 + 4 = 9 Then move on the subtraction. The addition answer moves to the front and you switch the other two numbers around to make 2 problems. 9-4 = 5 9-5 = 4 Today we do the same thing, only instead of addition and subtraction we use multiplication and division. Example: Create fact families for the following three numbers. 2 5 10 ANSWER: You can t do addition here. 2 + 5 = 7 not 10, so that proves you will need to start with multiplication. The largest number (10) is your
answer, so it stays on the right for both problems. You switch the other two numbers around to make 2 problems 2 x 5 = 10 5 x 2 = 10 Then move on the division (because it is the opposite of multiplication in math we call opposite the inverse). The multiplication answer moves to the front and you switch the other two numbers around to make 2 division problems. 10 2 = 5 10 5 = 2 The Answer is 2 x 5 = 10 5 x 2 = 10 10 2 = 5 10 5 = 2 Be careful because you will not always be able to create 4 problems (2 multiplication and 2 division). Example: Create fact families for the following three numbers. 6 6 36 ANSWER: You can t do addition here. 6 + 6 = 12 not 36, so that proves you will need to start with multiplication. The largest number (36) is your answer, so it stays on the right for both problems. The two small numbers are the SAME. If you switch the
two small numbers around you get the SAME PROBLEM again. So for a problem like this you only need 1 multiplication problem. 6 x 6 = 36 Then move on the division (because it is the opposite of multiplication in math we call opposite the inverse). The multiplication answer moves to the front and AGAIN you will only need to make 1 division problem for the same reason you only made 1 multiplication problem. 36 6 = 6 The Answer is 6 x 6 = 36 36 6 = 6 Instructions: Create fact family sets from the 3 numbers given. 1. 8 6 48
2. 10 4 40 3. 9 7 63 4. 12 11 132
5. 9 3 27 6. 5 5 25 7. Write the division problem for the following picture. The Answer is
8. Write the division problem for the following picture. The Answer is 9. 76 x 9 = 10. Cornelius buys 8 skateboards for his grandsons. Each skateboard cost $48. How much did Cornelius spend in all? The Answer is *Extra Work Never Hurt Anybody* 11. Lyle and Stanley attend a baseball card convention on Saturday. Lyle buys 6 posters for $7 each and 10 baseball cards for $2 each. Stanley buys 4 pennants for $12 each and 5 baseball caps for $6 each. How much did each boy spend? Who spent the most? Lyle spent Stanley spent spent more money.
12. Look at the amount of money below. Which amount, when written as a decimal will have a 5 in the tenths place? Picture F Picture G Picture H Picture J The Answer is (*Images used from Discovery Education)
13. Identify the place value of each digit in the number 214,658 2 = 1 = 4 = 6 = 5 = 8 = 14. What is the expanded form of 7,093? The Answer is 15. D Shawn buys 31 bags of chips. He keeps 7 bags of chips for himself and gives the remaining bags of chips to his 4 friends. If each of D Shawn s friends gets an equal number of bags of chips, how many bags of chips does each friend get? Each of D Shawn s friends gets bags of chips.
A N S W E R S Instructions: Create fact family sets from the 3 numbers given. Review the rules at the beginning of the assignment if you have forgotten. You will use the numbers given to create 2 multiplication and 2 division problems (UNLESS you have the same number twice then it will only be 1 multiplication and 1 division problem). The largest number goes on the answer side for multiplication. For division the largest number is the first number you write down on the problem. 1. 8 6 48 8 x 6 = 48 6 x 8 = 48 48 8 = 6 48 8 = 6
2. 10 4 40 10 x 4 = 40 4 x 10 = 40 40 4 = 10 40 10 = 4 3. 9 7 63 9 x 7 = 63 7 x 9 = 63 63 9 = 7 63 7 = 9
4. 12 11 132 12 x 11 = 132 11 x 12 = 132 132 11 = 12 132 12 = 11 5. 9 3 27 9 x 3 = 27 3 x 9 = 27 27 3 = 9 27 9 = 3 6. 5 5 25 5 x 5 = 25 25 5 = 5
7. Write the division problem for the following picture. How many total hearts do you have in the picture: 15 How many groups do you have: 3 How many hearts are in each group: 5 Put it together in a division problem and you have: 15 3 = 5 The Answer is 15 3 = 5
8. Write the division problem for the following picture. How many total suns do you have in the picture: 4 How many groups do you have: 4 How many suns in each group: 1 Put it together in a division problem and you have: 4 4 = 1 The Answer is 4 4 = 1
9. 76 x 9 = 6 8 4 tens +5 7 6 ones x 9 6 8 4 10. Cornelius buys 8 skateboards for his grandsons. Each skateboard cost $48. How much did Cornelius spend in all? Let s break apart this word problem. What is the question: How much did Cornelius spend in all? Is there any information in the word problem you do not need? No, we only have two numbers and we need both of them to solve the problem. What are your numbers? 8 and 48
What do the numbers stand for? 8 stands for skateboards 48 stands for dollars Do the numbers stand for the same word or different words? Different words (skateboards and dollars) Same word means + or - Different words means x or Are they any CLUE WORDS to help you figure out which operation (x or ) to use? Yes, in the question the phrase in all means x. What is your problem? 48 x 8 = Solve it. tens +6 4 8 ones x 8 3 8 4
The Answer is 3 8 4 *Extra Work Never Hurt Anybody* 11. Lyle and Stanley attend a baseball card convention on Saturday. Lyle buys 6 posters for $7 each and 10 baseball cards for $2 each. Stanley buys 4 pennants for $12 each and 5 baseball caps for $6 each. How much did each boy spend? Who spent the most? This is a multiple step question, the kind the STAAR test likes to put on its Math tests. First, let s see how much Lyle spent. 6 posters for $7 each means 6 x 7 = 42 10 baseball cards for $2 each means 10 x 2 = 20 Add the two products (answers to x problems) together. 42 + 20 = 62 (how much Lyle spent)
Second, let s see how much Stanley spent. 4 pennants for $12 each means 4 x 12 = 48 5 baseball caps for $6 each means 5 x 6 = 30 Add the two products (answers to x problems) together. 48 + 30 = 78 (how much Stanley spent) Finally, compare the two sums (answers to + problems) to see who spent more. 62 (for Lyle) < 78 (for Stanley) Stanley spent more. Lyle spent 62 Stanley spent 78 Stanley spent more money.
12. Look at the amount of money below. Which amount, when written as a decimal will have a 5 in the tenths place? The STAAR test may ask a question like this. Your child should go through each answer and write the decimal value beneath it. Picture F 1.10 Picture G 0.58
Picture H 0.45 Picture J 0.65 The question wants a 5 in the tenths place. The tenths place is the first place value AFTER the decimal point. So go through each answer and underline the digit after the decimal point. Only PICTURE G s answer 0.58 has a 5 in the tenths place. G The Answer is (*Images used from Discovery Education)
13. Identify the place value of each digit in the number 2 = hundred thousands 1 = ten thousands 214,658 4 = one thousands or thousands 6 = hundreds 5 = tens 8 = ones 14. What is the expanded form of 7,093? Expanded form means breaking a number apart, and showing the value (how much the digit is worth in the number) of each digit in an addition problem. If the number has a zero (0) in it you skip the value of that spot. 7 in the one thousands place is worth 7,000 0 in the hundreds place is worth nothing (skip it) 9 in the tens place is worth 90 3 in the ones place is worth 3
Put it altogether in an addition problem. The Answer is 7,000 + 90 + 3 15. D Shawn buys 31 bags of chips. He keeps 7 bags of chips for himself and gives the remaining bags of chips to his 4 friends. If each of D Shawn s friends gets an equal number of bags of chips, how many bags of chips does each friend get? A multiple step question the STAAR test may use. First, find out how many bags of chips D Shawn is giving to his friends. Subtract 31 and 7. 31-7 = 24 Second, D Shawn wants to give an equal number of bags of chips to his 4 friends. The phrase equal number almost always is a CLUE to use division. Divide 24 by 4. 24 4 = 6 So each one of D Shawn s friends will get 6 bags of chips. Each of D Shawn s friends gets 6 bags of chips.