Estimation Word Problems

Welcome to Sense or no Sense! Mr. Squeaks and Imani must decide whether the answers to the word problems are reasonable! In order to win the prize, they will need to use estimation in word problems. In word problems, estimation to check if our answers are reasonable is a useful skill. We can use estimation strategies such as rounding, using known facts and mental maths. First, read and then reread the problem to identify the important information. Then, use rounding or known facts. Next, use mental maths to find an estimate. Finally, compare the estimation to the original answer to decide whether or not it is reasonable. If the numbers are close, your maths is most likely correct. If the numbers are far apart, your maths most likely has a mistake and needs to be corrected. Here's the first question for Mr. Squeaks and Imani. Axel and Tank plan a family trip to Submersive Studios. Admission is sixty-seven pounds and ninety-nine pence for adults, and forty-two pounds and ninety-nine pence for children. Four adults and two children are going. Axel says it will cost three hundred and fifty-seven pounds and ninety-four pence altogether. Does his answer make sense or no sense? To decide whether the answer is reasonable, they will estimate. Sixty-seven pounds and ninety-nine pence is rounded to seventy pounds. There are four tickets at this price. Seventy times four equals two hundred and eighty. If we change forty-two pounds and ninety-nine pence to forty-five pounds, we can use known facts. Forty-five times two is ninety. Two hundred and eighty plus ninety equals three hundred and seventy pounds. Three hundred and seventy pounds is close to three hundred and fifty-seven pounds and ninety-four pence, so Axel's answer is reasonable. " Sense!" The next round is worth double and here is the question! Zuri and Freddie collected cans to recycle. Zuri collected six boxes with twenty-four cans in each. Freddie collected four boxes with thirty-seven cans in each. Freddie says he collected two hundred and ninety-two more cans than Zuri. Does his answer make sense? "Sense!" Mr. Squeaks answered incorrectly because he rushed and didn't estimate to check his answer. Here is how estimation would have helped him. Zuri had six boxes of twenty-four cans. What number is easier to work with for known facts than twenty-four? Twenty-five. What is six times twenty-five? One hundred and fifty. Freddie had four boxes of thirty-seven cans. What number do we round thirty-seven to? Forty. What is four times forty? One hundred and sixty. The question asks how many more, so we subtract. What is one hundred and sixty minus one hundred and fifty? Ten. Freddie's answer was not reasonable because he used addition instead of subtraction. It's the final round. They must get this correct or leave empty-handed! Nari and Gus are planning a party. They invited twenty-eight guests and want to have enough for two hot dogs each. Hot dogs come in packs of twelve. Nari says they need to buy five packs. Does his answer make sense or no sense? Pause the video and solve this problem to see what they should answer and press play when you are ready for the solution! Twenty-eight rounds to thirty. Thirty times two equals sixty. Twelve multiplied by five equals sixty. While they debate their answer, let's review! Remember, in word problems, estimating to check whether our answers are reasonable is a useful skill. First, read and reread the problem to identify the important information. Then round or change the numbers to ones that are easier to work with, or that we can use known facts to solve. Next, use mental maths to find an estimate. Finally, compare the estimation to the original answer to determine whether it is reasonable. Congratulations Imani, and you too, Mr. Squeaks!