Grade Level: 3rd Skill: Numbers Topic: Add and Subtract 5-Digit Numbers Goal: Find the sum of difference of two whole numbers between 0 and 10,000 Skill Description: Number Sense: Sum and difference up to ten thousands place The ability to find the sum (add) or difference (subtract) of two whole numbers between 0 and 10,000.

Sample Problems

 (1) If given two numbers, children know how to place the numbers vertically on top of each other correctly in order to add or subtract. Each place value must be aligned with the same place in the other number. (2) Where do you begin to add or subtract? With which number? ( begin with the number to the far right) (3) Adding: Children start at the right and work left. If the sum of a column is greater than or equal to ten, the one is carried to the next column to the left. (4) Subtracting: Align numbers on top of each other. Subtract each column starting at the right and working left. If the number being subtracted (the number on the bottom) is greater than the number it is subtracted from (top), then take one from the number in the next left column and add ten to the number you are subtracting from. (5) What is the definition of regrouping? (to rename one place value as 10 of the next lower place value) Define sum and difference? (+, -)

Learning Tips

 (1) Before beginning to add and subtract large numbers review with your child the strategies he/she has devised for solving small problems. If mastery of the basic combinations is weak, work very diligently to finally master these. Because larger problems often require sequential regrouping (needing to “carry” and “borrow” in adjoining columns) your child will have a lot to think about just becoming competent with this new series of tasks without having to stop and count up what the basic combination’s result is. (2) If you need to teach/provide practice in adding and subtracting larger numbers before the combinations are mastered provide a card with the unknown combinations written out. The child can refer to it while learning this new skill and come back to combination practice later. Being “behind” in one skill does not always mean that a new step in the learning sequence needs to be postponed. (3) Follow the healthy math practices that your child has been learning. For example, it is very important now that the digits in the problems be written in readable form, with ample space between problems that the columns can be kept straight. Crooked columns of numbers often lead to a tens-place digit, for example, being subtracted/added from/to a 100s-place digit. If your child keeps track with little numbers on top of the problem to show his/her regrouping efforts, there must be room for them to be legible. To work hard and not be able to read what has been accomplished, forcing one to start over, is very frustrating to children, and unnecessary. (4) Children should use manipulatives to add and subtract simple addition and subtraction problems for initial practice, to reinforce what the actual processes are. Counters can show children the process of subtraction by moving a specified number from one place-value column to another. (5) Use pennies to model regrouping to tens and use dimes to model regrouping to dollars, etc.

Online Resources

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Extra Help Problems

 (1) 60 + 18 _______ (78) (2) 98-52= (46) (some math problems should be written vertically and others horizontally) (3) 8,245-3,973 = (4272) (4) 889 + 79 = (968) (5) 5705 -795 = (4910) (6) 1828 + 3387 = (5215) (7) 2176 – 310 = (1866) (8) 9368 – 8144 = (1224) (9) 7050 + 46 = (7096) (10) 4538+ 3859 = (8397) (11) 6760 – 1155 = (5605) (12) 1155 - 170 = (985) (13) 5516 + 3705 = (9221) (14) 426 + 8292 = (8718) (15) 9742 – 269 = (9473) (16) 3819 + 1842 = (5661) (17) 170 + 9434= (9604) (18) 7050 – 1176 = (5874) (19) 3978 + 1453 = (5431) (20) 4565 – 310 = (4255) (21) 1047 + 785 = (1832) (22) 997 + 7739 = (8736) (23) 4881 – 83 = (4398) (24) 7859 + 46 = (7905) (25) 4851 + 2287 = (7138) (26) 16= 9 + (7)