GRADE 2 FLORIDA. Addition WORKSHEETS

Transcription

1 GRADE 2 FLORIDA Addition WORKSHEETS

2 Addition reviewing basic number facts Knowing your basic addition facts is helpful. It means you don t have to keep on working out the same answers all the time! 1 Finish the addition number wheels = = Fill in the missing numbers in these facts. a 5 2 = b 7 3 = c 5 = 9 d 6 7 = e 3 9 = f 7 = 15 3 Write 4 addition facts for each number. a 10 b 20 = 10 = 20 = 10 = 20 = 10 = 20 = 10 = 20 Grade Grade 2 2 ADDITION ADDITION MAFS.2.OA.2.2 1

3 Addition reviewing basic number facts 1 Finish these number facts. a 10 3 = b 10 6 = c 20 8 = d 20 7 = e 30 9 = f 30 2 = 2 Put in the missing numbers or signs to make these facts true. a 10 =15 b 7 3 = 10 c 6 = 12 d 10 = 17 e 10 = 18 f Solve these problems. Write the number facts. a Sara had 13 goldfish. Her cousin gave her 7 more. How many goldfish did she have altogether? b Omar had $5 before his birthday. After his birthday, he had $20. How much money was he given? (Hint: which part of the problem is missing?) Grade 2 Grade ADDITION 2 ADDITION MAFS.2.OA.1.1, 2.OA.2 MAFS.2.OA.2.2 2

4 Addition adding more than 2 numbers We can add more than 2 numbers at a time and we can add them in any order. Look at =? We know that 3 and 7 makes 10, so we can add them together first. Then we add 5 to = 15 is the same as = 15 1 Warm up by practicing these make 10 problems. a 0 10 = 10 b 3 = 10 c 1 = 10 d 9 = 10 e 5 = 10 f 4 = 10 g 8 = 10 h 6 = 10 i 2 = 10 2 Practice turning these addition facts around. a 2 5 = 5 2 = b 1 7 = = 3 Circle pairs of numbers that add to 10 first, then add what is left. a = 13 c = e = b = d = f = Grade Grade 2 2 ADDITION ADDITION MAFS.2.OA.2.2 3

5 Addition counting on Counting on is a good strategy to choose when adding 1, 2, or = 19 We start at 17 and count on 2 more Use the number track to help you count on. Finish the facts a 14 2 = b 23 3 = c 19 1 = d 17 3 = e 15 1 = f 24 2 = 2 How quickly can you finish these? = 16 1 = 13 1 = 20 1 = 22 1 = Time = 21 2 = 17 2 = 23 2 = 15 2 = Time = 11 3 = 23 3 = 17 3 = 21 3 = Time Grade Grade 2 2 ADDITION ADDITION MAFS.2.NBT OA.2 4

6 Addition counting on If we can count on by 1, 2, or 3, then we can count on by 10, 20 and 30. Look at =? We start at 17 and jump down the grid by 10s. 20 is 2 so we make 2 jumps = Practice counting by 10s by reading down the columns on the grid out loud. Now try doing it without looking at the grid. Give yourself a check mark for each column you can do. 2 Use the number grid to help you count on. Finish the facts. a = b = c = d = e = f = 3 Create your own addition facts by writing a number on the left for each fact. a 20 = b 10 = c 10 = d 30 = Grade Grade 2 2 ADDITION ADDITION MAFS.2.NBT OA.2 5

7 Addition using number lines Number lines are helpful tools to use when adding. Look at 24 7 =? We start at 24 and jump 7 spaces. It s important to remember to count the jumps or spaces, not the numbers! = 31 1 Jump along the number lines and finish each number fact. a 22 9 = b 27 7 = c 31 8 = Trace the jumps and finish the facts. a = b = c = Grade Grade 2 2 ADDITION ADDITION MAFS.2.NBT OA.2 6

8 Addition doubling 1 Warm up by matching these doubles facts. How quickly can you do it? The first one has been done for you double double double 5 double 2 double Count the base-ten blocks to help you finish the doubles facts. a b = = c d = = e f = = g h = = Grade Grade 2 2 ADDITION ADDITION MAFS.2.NBT OA.2 7

9 Addition bridge to 10 Number lines can help us to bridge. Look at 18 6 = We take 2 jumps to the nearest ten. This is 20. Now we need to jump 4 more.? = 24 1 Jump along these number lines. Finish the statements. a 17 6 = I jumped 3 to get to 20. Then I jumped 3 more. b 18 8 = I jumped to get to 20. Then I jumped more. c 16 7 = I jumped to get to 20. Then I jumped more. d 19 4 = I jumped to get to 20. Then I jumped more. Grade Grade 2 2 ADDITION ADDITION MAFS.2.NBT OA.2 8

10 Addition introducing the vertical format 1 Finish these addition facts in two ways. a T O b T O c T O = 15 4 = 10 6 = d T O e T O f T O 2 14 = = = Grade Grade 2 2 ADDITION ADDITION MAFS.2.NBT OA.2 9

11 Written methods addition to 99, no regrouping Using a written method to add is very similar to this version of the split strategy: = (4 3 ) (2 1 one) = 7 3 = 73 The difference is that we set the numbers up in place value columns and add the first For each addition, complete it with the split strategy and then use the written method. a = ( ) ( ) = = b = ( ) ( ) = = c = ( ) ( ) = = Grade Grade 2 2 ADDITION ADDITION MAFS.2.NBT NBT.5 10

12 Written methods addition to 99, no regrouping 2 Add these using the written method. Add the, then the. Write your answer neatly in line with the place value columns. a b c d 6 4 e 3 3 f Now try adding three 2 digit numbers using the written method: a b c Write the missing digits in these problems: a 2 b 3 c Grade Grade 2 2 ADDITION ADDITION MAFS.2.NBT NBT.5 11

13 Written methods addition to 99 with regrouping Here is a place value board that shows how regrouping works. If we have 10, we should regroup into a ten. = On the first place value board we can see that there are 3 and 11. We regroup 10 into 1 ten and we get 4 and 1 one. 10 = 1 ten 1 For each set of place value boards, regroup the into a ten and show the regrouped amount on the next board. Just use straight lines for (longs) and squares for (shorts). a b 2 Add the numbers shown in longs and shorts. Use the first place value board to show the longs and shorts combined and regroup them on the second board. Record the addition problem in the squares: = Grade 2 ADDITION 2.NBT.5 Grade 2 ADDITION MAFS.2.NBT

14 Written methods addition to 99 with regrouping Now that you have practiced regrouping on place value boards, we are going to apply this to a written strategy of addition where you have to regroup. Let s look at If we use longs and shorts in columns, it looks like this. Then, we regroup the and to get the answer, 72. Now look at the written method for addition when regrouping: 70 First, estimate the answer: = 70. You estimate by rounding to the nearest Add the : 3 9 = 12 Think of this as 1 ten and Write the 2 in the column and put the 1 in the 7 2 column. Now add the and write 7 in the column. Is our answer reasonable? Yes, because it is close to our estimate. 3 Try adding these 2 digit numbers using the written method. Start by writing your estimat a b c Grade Grade 2 2 ADDITION ADDITION MAFS.2.NBT NBT.5 Continued on page

15 Written methods addition to 99 with regrouping Continued from page Try adding these 2 digit numbers using the written method. Start by writing your estimat d e f g h i Solve these word problems using the written method: a I drove 39 mi on Thursday and 58 mi on Friday. How far did I drive altogether? b Our class sold 19 raffle tickets during the first week of sales and 59 raffle tickets during the second week. How many were sold altogether? Grade 2 Grade ADDITION 2 ADDITION MAFS.2.OA.1.1, 2.NBT.5, MAFS.2.NBT OA.1 14

16 Addition adding 3-digit numbers, no regrouping Once we know how to add 2-digit numbers we can also add 3-digit numbers =? hundred hundred 1 ten 3 2 hundreds hundreds and 3 and 7 is = Add the hundreds,, and separately to finish these facts. a = b = c = Grade Grade 2 2 ADDITION ADDITION MAFS.2.NBT NBT.7 15

17 Addition adding 3-digit numbers, no regrouping We can write these problems vertically, too. This helps us to work with the hundreds,, and separately. We start with the. 4 2 = 6 H T O Then we add the. 3 5 = 8 Then we add the hundreds. 2 1 = 3 hundreds hundred hundreds Finish these addition problems. Remember to start with the and then add the. a H T O b H T O c H T O Draw lines to match the problems with their sets of blocks. H T O H T O Grade 2 ADDITION 2.NBT.7 Grade 2 ADDITION MAFS.2.NBT