Category: Add and Subtract Whole Numbers

Definition Consider a table of values; represented by an independent variable (x) and a dependent variable (y). We often use atable of valuesto display the values we record. Using the table, we can find the relationship between the two variables and write it as a rule. There may be an increasing or decreasing pattern in…

Word problem 1 (on addition) Yesterday, John had 237 baseball cards. Today he got 105 more. How many cards does John have now? Solution Step 1: Number of baseball cards John had = 237 Number of cards John got more = 105 Step 2: Number of cards John has now = 237 + 105 =…

Definition A fact family is a group of math facts using the same numbers. In the case of addition and subtraction, you use three numbers and get four facts. For example, you can form a fact family using the three numbers 3, 10, and 13: 10 + 3 = 13, 3 + 10 = 13,…

Problem 1 Subtract 6804 2547 Solution Step 1: Align the numbers vertically. Step 2: Since 4 is less than 7, we need to regroup in the ones place. We cannot borrow from zero, so we need to regroup in tens place as well. We regroup 8 to get 7 in hundreds place and ten in…

Problem 1 Subtract 836 647 Solution Step 1: Line up the numbers vertically. Step 2: In ones column, 7 is bigger than 6. So we borrow from 3 in tens column. We cross out 3 and write a 2. We put borrowed 1 beside 6 to make it 16. Then we subtract 7 from 16…

Problem 1 Subtract the numbers 74 57 Solution Step 1: We line up the numbers vertically. Step 2: In the ones column, we cannot subtract 7 from 4 as 7 is greater than 4. So we borrow a ten from tens column. We strike off 7 and write a 6 and put a 1 beside…

Problem 1 Subtract the numbers 76 42 Solution Step 1: We line up the numbers vertically. Step 2: Here, subtract the numbers in the ones column first. 6 2 = 4. Write 4 below ones column. Step 3: Next subtract the numbers in the tens column. 7 4 = 3. Write down 3 below tens…

Problem 1 Subtract the numbers 17 8 Solution Method 1 We subtract the numbers using a number line here. On the number line, start from the larger number 17 and then make 8 jumps to the left to land on 9. This is the difference between 17 and 8. Method 2 Counting backwards We represent…

Problem 1 Find the sum 3473 + 53 + 682 Solution Step 1: We line up the numbers vertically. Step 2: The digits in ones column are added. 3 + 3 + 2 = 8. So 8 is written below ones column. Step 3: Then the digits in tens column are added. 7 + 5…

Problem 1 Find the sum 562 + 76 Solution Step 1: We line up the numbers vertically. Step 2: We add the digits in ones column. 2 + 6 = 8. 8 is written below ones column. Step 3: Then we add the digits in tens column. 6 + 7 = 13. 3 is written…