Missing Digits

12 x 2☐ = 34☐

252 x 7☐ = 1☐396

3☐3 x ☐53 = 18☐679

☐0 x 2☐0 = 15☐00

☐12 x 2☐9 = 13☐028

1☐40 x ☐42 = 98☐680

Each red box represents a missing digit.
Can you find out what they are?

A Mathematics Lesson Starter Of The Day

Starter of The Day Transum Mathematics Topics

Topics: Starter | Arithmetic | Problem Solving

Miriam Candelaria, Toa Baja, Puerto Rico
It is fun and a great day starter. I would really appreciate the answer key, though.
Transum,
Thanks Miriam, you'll find the answers to most starters right at the bottom of the page for those who have a Transum subscription.
Helsby High School, 10y4
Most of the class thought this was a good starter. Thank You
Mrs O'hagan's 3rd Yr Class, Holyrood Sec School Glasgow
We enjoyed the activity and would like similar but even more challenging!
6LC, West Kidlington Primary School
It was quite hard but we really enjoyed it!
Transum,
What strategies might you use to do this activity? Most people would probably reach for their calculator straight away but the task requires a more thoughtful approach. Each calculation has a different form and different suppositions can be made depending on the digits that are given. Trial and improvement with a planned range of possible missing digits and a calculator used wisely will help solve this puzzle. Each time the page is refreshed a different set of calculations will appear giving plenty of opportunity for practice.
Maths Brainy Badgers, United Kingdom
We found it fun and challenging in a good way.

How did you use this starter? Can you suggest how teachers could present or develop this resource? Do you have any comments? It is always useful to receive feedback and helps make this free resource even more useful for Maths teachers anywhere in the world.
Click here to enter your comments.

Previous Day | This starter is for 1 December | Next Day

Answers

12 x 29 = 348

252 x 73 = 18396

343 x 553 = 189679

60 x 260 = 15600

612 x 219 = 134028

1540 x 642 = 988680

Note to teacher: Doing this activity once with a class helps students develop strategies. It is only when they do this activity a second time that they will have the opportunity to practise those strategies. That is when the learning is consolidated. Click the button above to regenerate another version of this starter from random numbers.

Teacher, do your students have access to computers such as tablets, iPads or Laptops? This page was really designed for projection on a whiteboard but if you really want the students to have access to it here is a concise URL for a version of this page without the comments:

Transum.org/go/?Start=December1

However it would be better to assign one of the student interactive activities below.

Laptops In Lessons

The 1st December is the date to start opening the doors of the 2024 Mathematics Advent Calendar.

Transum.org/go/?to=Advent