Strategic+Word+problems

Stage Three 2015 were asked to create word problems which favoured a particular addition / subtraction strategy.

Below are some word problems that (hopefully) make you think!

Which is the most efficient strategy you can use to solve these problems? Use a different strategy to check and prove you are correct. Show the working out for both strategies in your book.

Which is the most efficient strategy?

If the problem was too easy how could you make it harder? Or easier?

Start with any you like.

“I had 4444 seeds and so did my friend. My neighbour and my teacher each had 2222 seeds. How many seeds all together? (Michaela)

I had 402 pieces of paper, but 108 of these got chewed up by the photocopier. How many pieces were left? (Michaela)

My bus was due at 7:45am and my mum dropped me off 41min early. What time did I arrive at the bus stop? (Jacinta)

If I had $899 and spent $399, how much money do I have left? (Simon)

I own an unusual Zoo. I have 2 elephants, 100 tigers, 60 whales, 78 monkeys and 117 zebras. How many animal feet in my zoo? (Rebecca B)

I had 597 pencils, but my dog chewed 278. How many do I have left? (oops, I missed who this was, please let me know)

The lens of my glasses is 30mm thick on both sides. Three other kids in my neighbourhood have glasses the same thickness. If we connected all our lenses flat against each other what thickness would they be? (Celeste)

I had 699 jellybeans in a jar. I had to share with my brother so I gave him exactly half. How many jellybeans did I give away?

Mark had 313 tickets at timezone. He ‘spent’ 294 on a cushion. How many tickets does he have left? (Kaitlyn)

Jake ran 100m in the super fast time of 14.3632 seconds. He ran again and did it in 16.6931 seconds. By how many seconds did Jake slow down? (Kyle)

"I earned $20.50 for washing Dad's car. I washed Dad's car again and got the same amount again. Then I washed my Mum's car and Grandma's car for $41

How much money do I have now?" (Bradley)

"I saved $100,000 for a new car. It cost $53,000. I decide to add higher suspension for $1,700. The suspension then broke so I replaced it for $1,200. I put new tyres on for $5,000. I buy new tinted windows for $10,000 and get 50% off the tint.

How much is left over?" (Harrison)

"I went to the shops to buy a party dress. The dress cost $48 and the shoes cost $79. How much did they cost altogether?" (Tara)

"I had $5,200,955 to spend. I bought a mansion for $2,600,477.50. I received $150,000 from the bank. I shared $75,000 with my friend.

How much money did I have left?" ( Matthew)