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How do you use estimation to check the sum of 437 and 529?

How do you use estimation to check the sum of 437 and 529?. In this lesson you will learn to check if your answers to story problems are reasonable by using front end estimation. Reasonable means it makes sense.

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How do you use estimation to check the sum of 437 and 529?

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  1. How do you use estimation to check the sum of 437 and 529?

  2. In this lesson you will learn to check if your answers to story problems are reasonable by using front end estimation.

  3. Reasonable means it makes sense.

  4. Not completing all steps in multi-step problems and not checking back to see if the answer makes sense.

  5. Front end estimation Rounding to the lead digit Look at the first digit 437 The 4 is in the hundred’s place so it’s value is 400.

  6. Prove with place value tools 437

  7. 437 using front end estimation is 400. Rounding to the lead digit.

  8. Front end estimation Rounding to lead digit Look at the first digit 529 The 5 is in the hundred’s place so it’s value is 500.

  9. Prove with place value tools 529

  10. 529 using front end estimation is 500. Rounding to the lead digit.

  11. 1 4 3 7 + 5 2 9 4 0 0 + 5 0 0 9 0 0 • 9 • 6 • 6

  12. Jack baked 232 cupcakes. Jill baked 318 cupcakes. They sold 115. How many do they have left? Jack 232 cupcakes. Jill 318 cupcakes. They sold 115.

  13. Jack 232 cupcakes. Jill 318 cupcakes. They sold 115. 232 + 318 -115 = How many cupcakes are left • 1 • 4 2 3 2 + 3 1 8 5 5 0 - 1 1 5 • cupcakes are left • 5 • 5 • 0 • 4 • 3 • 5

  14. Jack 232 cupcakes. 200 300 • Jill 318 cupcakes. 100 • They sold 115. 232 + 318 -115 = 435 cupcakes are left 200 + 300 -100 = 400 cupcakes are left

  15. In this lesson you have learned to check if your answers to story problems are reasonable by using front end estimation.

  16. Third grade is collecting canned goods for the food pantry. The goal is 1000 cans. In week one 122 cans were collected. In week two 315 cans were collected. In week three 450 cans were collected. How many are still needed to reach the goal?

  17. Goal is 1000 cans Cans collected: Week one: 122 Week two: 315 Week three: 450 +

  18. “ Story Problem Mix-Up” • Needed: 3 players and scrap paper strips • To Play: (play 3 rounds each player leads one) • -First player gives a topic (like the can drive) • -all players write a sentence including a number and action to go with the topic • -first player creates a story with all sentences • -each player solves, showing strategies used • -CHECK for reasonable answer using front end estimation! Compare and discuss

  19. Story Problem Bank • As players finish rounds of play in Story Problem Mix Up, record the story problems and file so partners or individual students can work on just solving and then checking using front end estimation.

  20. Front End Estimation Roll-a- thon! • Needed: 3 players, 3 dice, paper • To Play: each player gets 1 roll per round • Choose 2 or 3 dice, before roll say add or subtract. Keep track of each play. When all players have gone solve the equation. Use front end estimation to check if answer is reasonable. Compare and discuss.

  21. Jack and Jill need to bring 500 pails up the hill. Jack carried 224. Jill carried 231. They spilled 112! • Select the equation that tells how many more they need to carry? • Select the equation that uses front end estimation to check.

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