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Swimming Maths

Swimming personal bests maths challenge

A child-friendly sports challenge using personal bests to practise subtraction with real examples.

Quick answer

By working out your swimming personal bests, you can practice subtraction with real-life numbers and see how much faster you can swim!

Learning outcome

By the end of this page, you will be able to use subtraction to find out how much faster or slower you are compared to your personal best times in swimming. Success signs:
  • You can subtract two times to find the difference
  • You can compare your swimming times to see if you've improved
  • You can use subtraction to plan how much faster you want to swim
  • You can work out how much time you've saved or lost in a race

Why this matters

When you swim, you might want to know how much faster you can go compared to your last race. This helps you track your progress and set new goals. Swimming personal bests maths is useful for:
  • Planning training sessions
  • Understanding how much time you've improved
  • Setting new goals for races
  • Seeing your progress over time

How it works

To work out your swimming personal bests:
  1. Write down your swimming time for a race
  2. Write down your previous best time
  3. Subtract your previous time from your new time
  4. If the answer is negative, you've improved
  5. If the answer is positive, you've got slower

Examples you can see

Let's say you swam the 50m freestyle in 45 seconds last week. This week you swam it in 42 seconds. To find out how much faster you got, you subtract:
  • 45 seconds - 42 seconds = 3 seconds
This means you swam 3 seconds faster this week than last week! Another example: If you swam 100m backstroke in 1 minute 15 seconds last month, and this month you swam it in 1 minute 10 seconds, you subtract:
  • 1 minute 15 seconds - 1 minute 10 seconds = 5 seconds
You're 5 seconds faster this month!

Try it as a mini adventure

Swimming Challenge: Time Trial! You're a swimmer preparing for a competition. You want to track your progress over 4 weeks. Week 1: You swim 200m butterfly in 2 minutes 30 seconds. Week 2: You swim 200m butterfly in 2 minutes 25 seconds. Week 3: You swim 200m butterfly in 2 minutes 20 seconds. Week 4: You swim 200m butterfly in 2 minutes 15 seconds. Your challenge:
  • Week 1 to Week 2: How much faster were you? Answer: 5 seconds faster
  • Week 2 to Week 3: How much faster were you? Answer: 5 seconds faster
  • Week 3 to Week 4: How much faster were you? Answer: 5 seconds faster
  • Overall improvement from Week 1 to Week 4: Answer: 15 seconds faster

Common mistakes

  • Mistake: Subtracting the new time from the old time instead of the other way around.
    Why it happens: Children might get confused about which number to subtract from which.
    Fix: Remember: If your new time is smaller than your old time, you've improved. If your new time is bigger than your old time, you've gotten slower.
  • Mistake: Forgetting to convert minutes to seconds when subtracting.
    Why it happens: Some children think they can subtract minutes and seconds separately without converting.
    Fix: If you're working with times that include minutes and seconds, convert everything to seconds first. For example, 1 minute 15 seconds = 75 seconds.
  • Mistake: Not writing down the times clearly.
    Why it happens: It's easy to mix up times when writing quickly.
    Fix: Always write times in the same way: minutes and seconds (e.g., 1 min 30 sec) and double-check your numbers.

Parent and carer guide

You can help your child with swimming personal bests maths in just 5-10 minutes:
  • Ask your child to tell you their swimming times for different races
  • Help them write down the times neatly
  • Work together to subtract the times and see how much faster or slower they are
  • Encourage them to set a goal for their next race
  • Use a stopwatch or timer to make it real and fun
What to say:
  • "Let's see how much faster you can swim!"
  • "How much time did you save this week?"
  • "Can you beat your personal best?"
What not to worry about:
  • It's okay if your child makes mistakes - they're learning!
  • Don't focus on the exact times, focus on the learning
  • Encourage effort, not just results

Practice questions

  1. Tom swam 100m freestyle in 1 minute 20 seconds last week. This week he swam it in 1 minute 15 seconds. How much faster was he this week?
    Answer: 5 seconds faster
  2. Jessica swam 50m backstroke in 40 seconds last month. This month she swam it in 38 seconds. How much faster was she this month?
    Answer: 2 seconds faster
  3. Sam swam 200m breaststroke in 3 minutes 10 seconds last year. This year he swam it in 3 minutes 5 seconds. How much faster was he this year?
    Answer: 5 seconds faster
  4. Lily swam 100m butterfly in 1 minute 30 seconds last week. This week she swam it in 1 minute 35 seconds. How much slower was she this week?
    Answer: 5 seconds slower
  5. Ben swam 50m freestyle in 35 seconds last month. This month he swam it in 30 seconds. How much faster was he this month?
    Answer: 5 seconds faster

FAQ

What is a personal best in swimming?

A personal best is the fastest time you've ever achieved in a particular swimming event.

Why do swimmers track their personal bests?

Swimmers track personal bests to see their progress, set goals, and know how much they've improved over time.

How do I subtract times correctly?

First, convert all times to the same unit (like seconds). Then subtract the smaller number from the larger one. If the answer is positive, you got slower. If negative, you got faster.

Can I use subtraction for other sports too?

Yes! You can use subtraction to track your progress in running, cycling, jumping, or any sport where you record times or scores.

How can I make this more fun?

You can make it a game by setting weekly goals, using a chart to track your progress, or even creating a swimming race with friends!